Food-related lactic acid bacteria (LAB) as well as human gut commensals such as bifidobacteria can de novo synthesize and supply vitamins. This is important since humans lack the biosynthetic capacity for most vitamins and these must thus be provided exogenously. Although vitamins are present in a variety of foods, deficiencies still occur, mainly due to malnutrition as a result of insufficient food intake and because of poor eating habits. Fermented milks with high levels of B-group vitamins (such as folate and riboflavin) can be produced by LAB-promoted and possibly bifidobacteria-promoted biosynthesis. Moreover, certain strains of LAB produce the complex vitamin cobalamin (or vitamin B12). In this review, fermented foods with elevated levels of B-group vitamins produced by LAB used as starter cultures will be covered. In addition, genetic abilities for vitamin biosynthesis by selected human gut commensals will be discussed. Show
Graphical abstract
Highlights► Humans lack the biosynthetic capacity for most vitamins. ► Vitamins must thus be provided exogenously by nutritionally balanced diets. ► Members of the human gut microbiota can supply their host with microbially synthesized vitamins. ► Fermented milks with high levels of B-group vitamins can be produced by lactic acid. IntroductionVitamins are essential micronutrients that are normally found as precursors of various enzymes that are necessary for vital biochemical reactions in all living cells. Humans are incapable of synthesizing most vitamins and they consequently have to be obtained exogenously. The use of vitamin-producing microorganisms may represent a more natural and consumer-friendly alternative to fortification using chemically synthesized pseudo-vitamins, and would allow the production of foods with elevated concentrations of vitamins that are less likely to cause undesirable side-effects. The biochemical pathways involved in B-vitamin biosynthesis by food microorganisms have previously been described in detail [1••]. The human gastrointestinal tract (GIT) is colonized by a vast array of microorganisms known as the gut microbiota, with up to 1011 bacteria per gram of intestinal content [2]. Apart from its impact on different human functions [2], the intestinal microbiota plays a pivotal role in food digestion and energy recovery, while it can also act as an important supplier of vitamins. In humans it has been shown that members of the gut microbiota are able to synthesize vitamin K as well as most of the water-soluble B vitamins, such as biotin, cobalamin, folates, nicotinic acid, panthotenic acid, pyridoxine, riboflavin and thiamine [3]. In contrast to dietary vitamins, which are adsorbed in the proximal tract of the small intestine, the predominant uptake of microbially produced vitamins occurs in the colon [4, 5]. The genus Bifidobacterium currently encompasses 39 species (reviewed in [6]) and its members represent key components of the human gut microbiota [7, 8, 9•]. Several reports have highlighted the importance of bifidobacteria in regulating intestinal homeostasis, modulating local and systemic immune responses, and protecting against inflammatory diseases and infections [10, 11]. In addition, some bifidobacterial species are claimed to convert a number of dietary compounds into health-promoting bioactive molecules, such as conjugated linoleic acid and certain vitamins [12, 13]. Particular bifidobacterial strains have been shown to exhibit vitamin production [14, 15, 16], although their biosynthetic abilities have not been examined in detail and will be discussed here. The B-group vitamin folate is involved in various essential metabolic functions such as DNA replication, repair and methylation, and synthesis of nucleotides, vitamins and certain amino acids. De novo synthesis of folate requires both 6-hydroxymethyl-7,8-dihydropterin pyrophosphate (DHPPP) and para-aminobenzoic acid (pABA). Folate biosynthetic properties of bifidobacteria have been verified, though folate biosynthesis appears to be restricted to certain species/strains, leading to the identification of high level (e.g. Bifidobacterium bifidum and Bifidobacterium longum subsp. infantis) and low level folate-producing species (e.g. Bifidobacterium breve, Bifidobacterium longum subsp. longum and Bifidobacterium adolescentis) [16]. Such findings have been confirmed by in vivo studies: administration of high-producing folate strains was shown to cause an increased faecal level of folate in both rats and humans [17, 18]. With the advent of microbial genomics it is now possible to interrogate the genetic make-up of microorganisms for specific features (reviewed in [19]). The first decade of molecular exploration of gut commensals, in particular bifidobacteria and lactobacilli, has afforded unprecedented insights into the genetic adaptation of these bacteria to the human gut through the decoding of their genome sequences (probiogenomics) [20]. Genomic adaptation is obvious in many bifidobacterial genomes where over 9% of annotated genes encode enzymes involved in carbohydrate metabolism [21, 22]. However, the dissection of bifidobacterial genomes has also revealed interesting features with respect to vitamin biosynthetic capabilities (Figure 1). No complete pathways for the biosynthesis of biotin, panthothenate, pyridoxine, cobalamin and menaquinone are present in any of the so far sequenced bifidobacterial genomes, yet they are predicted to encode complete pathways for the synthesis of shikimate and thus are expected to produce chorismate [23, 24, 25, 26, 27, 28•, 29, 30], a precursor for folate biosynthesis. However, although all available complete bifidobacterial genomes are expected to specify aminodeoxychorismate synthase (EC 2.6.1.85), a gene specifying a putative 4-amino-4-deoxychorismate lyase (EC 4.1.3.38) can only be found on the genome of B. adolescentis ATCC15703 and B. dentium Bd1 [27], which are thus expected to accomplish de novo biosynthesis of pABA (Figure 2). By contrast, B. animalis subsp. lactis does not appear to possess the entire pathway for DHPPP biosynthesis or the gene encoding dihydropteroate synthase (EC 2.5.1.15) (Figure 2). Thus, B. animalis subsp. lactis is expected to be auxotrophic for folates or DHP, and would therefore be incapable of folate biosynthesis, even in the presence of pABA (Figure 2). Lactobacilli are another common group of human gut commensals and have recently been investigated as possible folate producers [31]. The genus Lactobacillus contains more than 100 recognized species displaying a remarkable phylogenetic, phenotypic and ecological diversity [32, 33]. The genetic characterization of lactobacilli is better developed than that of bifidobacteria, but the molecular mechanisms driving their interaction with the human gut still remain largely unknown (reviewed in [20]). Owing to their commercial potential, the ability to produce folate has been investigated in several lactobacilli from a variety of ecological origins. In this context, lactobacilli from various fermented foods have been investigated as starter cultures for the manufacture of folate-fortified dairy products, while lactobacilli isolated from the human gut have been explored as folate-producing probiotics [34, 35, 36, 37, 38, 39•]. The availability of genome sequences of various lactobacilli provided an important contribution to the genetics underlying folate biosynthesis in this group of microorganisms [40]. For example, lactobacilli do not appear to harbour the genetic determinants for de novo pABA synthesis, with the exception of Lactobacillus plantarum WCFS1 [41], suggesting that the vast majority of lactobacilli are unable to synthesize folate in the absence of pABA. Riboflavin (vitamin B2) plays an essential role in cellular metabolism, being the precursor of the coenzymes flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD), which both act as hydrogen carriers in many biological redox reactions. Microbial riboflavin biosynthesis from the precursors guanosine triphosphate (GTP) and d-ribulose 5-phosphate occurs through seven enzymatic steps, with detailed studies performed for Bacillus subtilis [42] and Escherichia coli [43], and reviewed recently [44]. Riboflavin concentrations can vary in certain dairy products due to processing technologies and to the action of microorganisms during food processing [1••]. It has been shown that most yoghurt starter cultures decrease riboflavin concentrations whereas others can increase levels of this essential vitamin up to 160% of the initial concentration present in unfermented milk [45]. Selection of spontaneous roseoflavin-resistant mutants was found to be a reliable method to obtain natural riboflavin-overproducing strains of various species commonly used in the food industry [46]. So far fragmentary information is available on the de novo synthesis of riboflavin by enteric bacteria, in the case of bifidobacteria the enzymes needed for the biosynthesis of this vitamin seem to be partially or completely absent from the majority of currently available bifidobacterial genomes [19]. However, one cannot exclude the possibility that multiple, co-existing microbial species are capable of de novo synthesis. The term vitamin B12 is generally used to describe a type of cobalt corrinoid, particularly of the cobalamin (cbl) group. Animals, plants and fungi are incapable of cobalamin production and it is the only vitamin that is exclusively produced by microorganisms, particularly by anaerobes [47, 48, 49]. One of the first model organisms used for the study of biosynthesis was P. freudenreichii that is used in the commercial production of vitamin B12. Lactobacillus reuteri CRL1098 was shown to be the first LAB strain able to produce a cobalamin-like compound with an absorption spectrum closely resembling that of standard cobalamin but with a different elution time, while cobalamin production was confirmed using different bioassays [50]. However, the biological activity of this pseudovitamin B12 is still not clear. Genetic evidence of cobalamin biosynthesis by L. reuteri CRL 1098 was then obtained and it was shown that at least 30 genes are involved in the de novo synthesis of the vitamin (Figure 3). The genetic organization (cob and cbi genes) are very similar to those of Salmonella enterica and Listeria innocua [51]. Recently, the genetic pathway responsible of the de novo synthesis of vitamin B12 by L. reuteri was described for two L. reuteri strains [52]. One distinctive characteristic of the cob cluster of L. reuteri is the presence of hem genes in the middle of the cluster. In the respiratory organisms Listeria and Salmonella with similar cob clusters, the hem genes are located at a different position on their genome. The presence of the hem genes in the cob cluster is a characteristic that has only been observed in certain genomes of Clostridium [53]. Recently, the transcription of a vast set of genes involved in cobalamin synthesis in sourdough prepared with strain L. reuteri ATCC 55730 was described [54]. In addition to strain CRL1098, other L. reuteri strains were shown to be capable of producing some corrinoids such as L. reuteri DCM 20016 [55], JCM1112 [36] and CRL 1324 and 1327, strains isolated from human vagina [56]. Recently, a reuterin-producing strain of L. coryniformis was shown to produce a cobalamin-type compound [57]. Notably, propionibacteria and L. reuteri normally occur in the human intestine and may thus (partially) fulfil the vitamin B12 requirement of the host. Besides riboflavin, folate and vitamin B12, increased levels of other B-group vitamins, for example, niacin and pyridoxine, have been reported for certain LAB used in yoghurt, cheese, and fermentations [58, 59]. For example, increases in thiamine and pyridoxine concentration were demonstrated as a result of soy fermentation with Streptococcus thermophilus ST5 and Lactobacillus helveticus R0052, or B. longum R0175 [60]. Vitamin K acts as a co-factor for the enzyme that converts specific glutamyl residues in a limited number of proteins to γ-carboxyglutamyl (Gla) residues. The daily requirement for vitamin K is fulfilled by dietary phylloquinone that is present in plants, and, to an undetermined extent, by bacterially produced polyisoprenyl-containing compounds known as menaquinones synthesized in the human gut [61]. However, menaquinone synthesis may not be fully dependent on the gut microbiota as animals lacking a gut microbiota can still produce menaquinone [62]. Although whole genome sequencing and assembly have historically been used for the study of single organisms, recent reports have shown the validity of this approach to investigate mixed microbial communities [2, 63, 64]. In this context, sampling genetic information of the human gut microbiota, also known as human gut microbiome, allowed us to obtain insights into the genetic features of enteric bacteria [64]. In order to delineate if and to what extent the enteric microbiome provides physiological features that were not evolved by its human host, the metabolic potential of microbial sequences was analysed through the classification of all identified microbial genes based on the Kyoto Encyclopedia of Genes and Genomes as well as the Clustered Orthologous Groups (COG). These analyses showed that the distal gut microbiome of two subjects is enriched for a variety of COGs involved in synthesis of essential amino acids and vitamins, such as those required for the synthesis of deoxyxylulose 5-phosphate (DXP), a precursor of the vitamins thiamine and pyrodoxal [64]. Recently, the combination of 22 newly sequenced faecal metagenomes of individuals from four countries allowed the identification of three robust clusters, named enterotypes, which are not nation or continent-specific [65••]. Notably, vitamin metabolism pathways were shown to be highly represented in all enterotypes, while two enterotypes were particularly enriched in genes that specify the biosynthetic enzymes for biotin, riboflavin, pantothenate, ascorbate, thiamine and folate production. These phylogenetic and functional differences among enterotypes thus reflect different combinations of microbial trophic chains with a probable impact on synergistic interrelations with the human host [65••]. Recently, transcriptomic studies directed to explore upregulated genes of bifidobacteria residing in faecal samples of adult subjects identified the presence of bifidobacterial genes predicted to be involved in the biosynthesis of several B-vitamins and folate that are highly expressed when bifidobacteria are in their natural ecological niche [66, 67, 68]. Since it is nearly impossible to quantify or demonstrate vitamin production by individual organisms of the human microbiome using traditional methods (e.g. HPLC, microbiological assays), these and other ‘omics’ approaches can provide evidence for such in situ vitamin production, while also allowing the development of methodologies to increase their production. Section snippetsConclusionsThe increase of B-group vitamin concentrations in fermented/functional foods is possible through judicious selection of microbial species and cultivation conditions. It is expected that the food industry will exploit novel and efficient vitamin-producing strains to produce fermented products. Such products are expected to provide economic benefits to food manufacturers since increased ‘natural’ vitamin concentrations would be an important value-added trait without increasing production costs. References and recommended readingPapers of particular interest, published within the period of review, have been highlighted as: • of special interest •• of outstanding interest AcknowledgementsThis work was financially supported by the Cariparma Bank Foundation to MV. DvS is a member of The Alimentary Pharmabiotic Centre and the Alimentary Glycoscience Research Cluster, both funded by Science Foundation Ireland (SFI), through the Irish Government's National Development Plan (Grant numbers 07/CE/B1368 and 08/SRC/B1393, respectively). JGL, FS and GSdG would like to thank the CONICET, ANPCyT and CIUNT for their financial contributions. References (68)
Biotin production by bifidobacteriaJ Nutr Sci Vitaminol (Tokyo)(1994) Probiotic properties of bifidobacteriaBifidobacteria: Genomics and Molecular Aspects(2010) Exploring the diversity of the bifidobacterial population in the human intestinal tractAppl Environ Microbiol(2009) B-group vitamin production by lactic acid bacteria – current knowledge and potential applicationsJ Appl Microbiol(2011) Host-bacterial mutualism in the human intestineScience(2005) Intestinal flora and endogenous vitamin synthesisEur J Cancer Prev(1997) Intestinal absorption of water-soluble vitamins: an updateCurr Opin Gastroenterol(2006) Colonic absorption of menaquinone-4 and menaquinone-9 in ratsJ Nutr(1992) Genomics and ecological overview of the genus BifidobacteriumInt J Food Microbiol(2011) Microbiomic analysis of the bifidobacterial population in the human distal gutISME J(2009) Diversity of bifidobacteria within the infant gut microbiotaPLoS ONE(2012) Interaction of probiotics and pathogens – benefits to human health?Curr Opin Biotechnol(2010) Probiotics, immune function, infection and inflammation: a review of the evidence from studies conducted in humansCurr Pharm Des(2009) Fermented functional foods based on probiotics and their biogenic metabolitesCurr Opin Biotechnol(2005) Comparative studies on synthesis of water-soluble vitamins among human species of bifidobacteriaAgric Biol Chem(1985) Folate production by bifidobacteria as a potential probiotic propertyAppl Environ Microbiol(2007) Administration of folate-producing bifidobacteria enhances folate status in Wistar ratsJ Nutr(2007) Quantification of folic acid in human feces after administration of Bifidobacterium probiotic strainsJ Clin Gastroenterol(2008) Genomics as a means to understand bacterial phylogeny and ecological adaptation: the case of bifidobacteriaAntonie Van Leeuwenhoek(2007) Genome-scale analyses of health-promoting bacteria: probiogenomicsNat Rev Microbiol(2009) Genomics of Actinobacteria: tracing the evolutionary history of an ancient phylumMicrobiol Mol Biol Rev(2007) Analysis of predicted carbohydrate transport systems encoded by Bifidobacterium bifidum PRL2010Appl Environ Microbiol(2012) The genome sequence of Bifidobacterium longum reflects its adaptation to the human gastrointestinal tractProc Natl Acad Sci USA(2002) Comparison of the complete genome sequences of Bifidobacterium animalis subsp. lactis DSM 10140 and Bl-04J Bacteriol(2009) 2023, Ageing Research Reviews Show abstractNavigate Down The microbiota-gut-brain axis or simple gut-brain axis (GBA) is a complex and interactive bidirectional communication network linking the gut to the brain. Alterations in the composition of the gut microbiome have been linked to GBA dysfunction, central nervous system (CNS) inflammation, and dopaminergic degeneration, as those occurring in Parkinson’s disease (PD). Besides inflammation, the activation of brain microglia is known to play a central role in the damage of dopaminergic neurons. Inflammation is attributed to the toxic effect of aggregated α-synuclein, in the brain of PD patients. It has been suggested that the α-synuclein misfolding might begin in the gut and spread "prion-like", via the vagus nerve into the lower brainstem and ultimately to the midbrain, known as the Braak hypothesis. In this review, we discuss how the microbiota-gut-brain axis and environmental influences interact with the immune system to promote a pro-inflammatory state that is involved in the initiation and progression of misfolded α-synuclein proteins and the beginning of the early non-motor symptoms of PD. Furthermore, we describe a speculative bidirectional model that explains how the enteric glia is involved in the initiation and spreading of inflammation, epithelial barrier disruption, and α-synuclein misfolding, finally reaching the central nervous system and contributing to neuroinflammatory processes involved with the initial non-motor symptoms of PD. 2022, Medicine in Microecology Show abstractNavigate Down Dietary fiber intake in humans is nowadays substantially decreased as compared to the communities of ancestral populations. Accompanying that, the incidences of inflammatory bowel disease (IBD), allergy, and other autoimmune diseases are steadily increasing over the past 60 years, especially in high-income countries, which is partly attributed to the changing dietary habit in modern societies. Chronic inflammation triggered by immune disorders is the central part of the pathophysiology of various non-communicable diseases. Dietary fiber intake is inexorably linked to the gut microbiome leading to the reduction of inflammation. This review explores how dietary fibers modulate the gut microbiota composition and function leading to the alteration of host physiology. High-fiber dietary regime has been consistently shown to increase the microbiome alpha diversity and short-chain fatty acids (SCFAs)-producing bacteria in the human gut. SCFAs are the main players in the interplay between diet, microbiota, and host health. In clinical settings, therapies with high fiber or SCFA supplementations are proposed for inflammatory diseases. However, due to greater variations in the dosage, type, and duration of dietary fiber intervention in different clinical trials, the effects remain controversial. Unraveling the mechanisms exerted by dietary fiber in synergy with the gut microbiome in human pathophysiology holds a promising prospect in guiding next-generation precision therapies. Probiotics for Otolaryngologic Disorders2022, Otolaryngologic Clinics of North America Diet Strategies for the Patient with Chronic Kidney Disease2022, Physician Assistant Clinics Supplementing cholamine to diet lowers laying rate by promoting liver fat deposition and altering intestinal microflora in laying hens2022, Poultry Science Show abstractNavigate Down The effects of cholamine, a raw material for synthesis of some active lipids, are unknown in poultry. To address this, 180 52-wk-old Hyline laying hens were randomly divided into 3 groups (20 replicates per group with three hens per replicate). The control group and the treatment groups (treatment 1 and 2) were fed basal diet and the diet supplemented with 500 or 1,000 mg of cholamine per kilogram of the diet for 35 d, respectively. The data showed that supplementary cholamine significantly lowered egg production, daily feed intake, serum high-density lipoprotein cholesterol level, liver index, and the percentages of C15:0 and C20:0 in fatty acid composition of liver, significantly elevated hepatic triglyceride content, the ratio of villus height to crypt depth (P < 0.05), and the percentage of C18:2n−6 and the ratio of n−6 to n−3 polyunsaturated fatty acids in liver fat (P < 0.10). Moreover, supplementary cholamine altered the relative abundance of some intestinal bacteria with a decrease in the alpha biodiversity (P < 0.10). Additionally, transcriptome analysis on the livers of the treatment vs. the control groups identified 1,151 up- and 914 down-regulated differentially expressed genes (DEGs), and pathway analysis revealed that the suppressed Notch signaling pathway and the enhanced Oxidative phosphorylation pathway were enriched with DEGs. Particularly, fat absorption, transport and oxidative phosphorylation-related DEGs (e.g., FABP1, APOA4, and PCK1) were significantly induced, but fatty acid synthesis, and lipid package and secretion-related DEGs (e.g., FASN, SCD, and MTTP) were not. In conclusion, supplementary cholamine may lower egg production by promoting hepatic lipid deposition and reducing abundances of beneficial intestinal bacteria and microfloral biodiversity in laying hens. Microbiota in a long survival discourse with the human host2023, Archives of Microbiology Research article Metabolism, Volume 69, 2017, pp. 76-86 Show abstractNavigate Down Due to immunomodulatory properties, vitamin D status has been implicated in several diseases beyond the skeletal disorders. There is evidence that its deficiency deteriorates the gut barrier favoring translocation of endotoxins into the circulation and systemic inflammation. Few studies investigated whether the relationship between vitamin D status and metabolic disorders would be mediated by the gut microbiota composition. We examined the association between vitamin D intake and circulating levels of 25(OH)D with gut microbiota composition, inflammatory markers and biochemical profile in healthy individuals. In this cross-sectional analysis, 150 young healthy adults were stratified into tertiles of intake and concentrations of vitamin D and their clinical and inflammatory profiles were compared. The DESeq2 was used for comparisons of microbiota composition and the log2 fold changes (log2FC) represented the comparison against the reference level. The association between 25(OH)D and fecal microbiota (16S rRNA sequencing, V4 region) was tested by multiple linear regression. Vitamin D intake was associated with its concentration (r = 0.220, p = 0.008). There were no significant differences in clinical and inflammatory variables across tertiles of intake. However, lipopolysaccharides increased with the reduction of 25(OH)D (p-trend < 0.05). Prevotella was more abundant (log2FC 1.67, p < 0.01), while Haemophilus and Veillonella were less abundant (log2FC − 2.92 and − 1.46, p < 0.01, respectively) in the subset with the highest vitamin D intake (reference) than that observed in the other subset (first plus second tertiles). PCR (r = − 0.170, p = 0.039), E-selectin (r = − 0.220, p = 0.007) and abundances of Coprococcus (r = − 0.215, p = 0.008) and Bifdobacterium (r = − 0.269, p = 0.001) were inversely correlated with 25(OH)D. After adjusting for age, sex, season and BMI, 25(OH)D maintained inversely associated with Coprococcus (β = − 9.414, p = 0.045) and Bifdobacterium (β = − 1.881, p = 0.051), but significance disappeared following the addition of inflammatory markers in the regression models. The role of vitamin D in the maintenance of immune homeostasis seems to occur in part by interacting with the gut microbiota. The attenuation of association of bacterial genera by inflammatory markers suggests that inflammation participate in part in the relationship between the gut microbiota and vitamin D concentration. Studies with appropriate design are necessary to address hypothesis raised in the current study. Research article Clinical Nutrition, Volume 37, Issue 1, 2018, pp. 37-55 Show abstractNavigate Down Non-alcoholic fatty liver disease (NAFLD) is a common liver disease in Western countries. Metabolic disorders which are increasing in prevalence, such as dyslipidaemias, obesity and type 2 diabetes, are closely related to NAFLD. Insulin resistance is a prominent risk factor for NAFLD. Marine omega-3 (n-3) polyunsaturated fatty acids (PUFAs) are able to decrease plasma triacylglycerol and diets rich in marine n-3 PUFAs are associated with a lower cardiovascular risk. Furthermore, marine n-3 PUFAs are precursors of pro-resolving and anti-inflammatory mediators. They can modulate lipid metabolism by enhancing fatty acid β-oxidation and decreasing de novo lipogenesis. Therefore, they may play an important role in prevention and therapy of NAFLD. This review aims to gather the currently information about marine n-3 PUFAs as a therapeutic approach in NAFLD. Actions of marine n-3 PUFAs on hepatic fat metabolism are reported, as well as studies addressing the effects of marine n-3 PUFAs in human subjects with NAFLD. A total seventeen published human studies investigating the effects of n-3 PUFAs on markers of NAFLD were found and twelve of these reported a decrease in liver fat and/or other markers of NAFLD after supplementation with n-3 PUFAs. The failure of n-3 PUFAs to decrease markers of NAFLD in five studies may be due to short duration, poor compliance, patient specific factors and the sensitivity of the methods used. Marine n-3 PUFAs are likely to be an important tool for NAFLD treatment, although further studies are required to confirm this. Research article Gut Microbes Take Their VitaminsCell Host & Microbe, Volume 15, Issue 1, 2014, pp. 5-6 Show abstractNavigate Down The dense microbial ecosystem within the gut is connected through a complex web of metabolic interactions. In this issue of Cell Host & Microbe, Degnan et al. (2014) establish the importance of different vitamin B12 transporters that help a Bacteroides species acquire vitamins from the environment to maintain a competitive edge. Research article Stability of vitamin B12 with the protection of whey proteins and their effects on the gut microbiomeFood Chemistry, Volume 276, 2019, pp. 298-306 Show abstractNavigate Down Cobalamin degrades in the presence of light and heat, which causes spectral changes and loss of coenzyme activity. In the presence of beta-lactoglobulin or alpha-lactalbumin, the thermal- and photostabilities of adenosylcobalamin (ADCBL) and cyanocobalamin (CNCBL) are increased by 10–30%. Similarly, the stabilities of ADCBL and CNCBL are increased in the presence of whey proteins by 19.7% and 2.2%, respectively, when tested in gastric juice for 2 h. Due to the limited absorption of cobalamin during digestion, excess cobalamin can enter the colon and modulate the gut microbiome. In a colonic model in vitro, supplementation with cobalamin and whey enhanced the proportions of Firmicutes and Bacteroidetes spp. and reduced those of Proteobacteria spp., which includes pathogens such as Escherichia and Shigella spp., and Pseudomonas spp. Thus, while complex formation could improve the stability and bioavailability of cobalamin, these complexes might also mediate gut microecology to influence human nutrition and health. Research article Biosynthesis and cellular content of folate in bifidobacteria across host species with different dietsAnaerobe, Volume 30, 2014, pp. 169-177 Show abstractNavigate Down Bifidobacteria, one of the most common bacteria of the intestinal tract, help establish balance in the gut microbiota and confer health benefits to the host. One beneficial property is folate biosynthesis, which is dependent on species and strains. It is unclear whether the diversity in folate biosynthesis is due to the adaptation of the bifidobacteria to the host diet or whether it is related to the phylogeny of the animal host. To date, folate production has been studied in the bifidobacteria of omnivorous, and a few herbivorous, non-primate hosts and humans, but not in carnivores, non-human primates and insects. In our study we screened folate content and composition in bifidobacteria isolated from carnivores (dog and cheetah), Hominoidea omnivorous non-human primates (chimpanzee and orangutan) and nectarivorous insects (honey bee). Bifidobacterium pseudolongum subsp. globosum, a species typically found in non-primates, was isolated from dog and cheetah, and Bifidobacterium adolescentis and Bifidobacterium dentium, species typically found in humans, were respectively obtained from orangutan and chimpanzee. Evidence of folate biosynthesis was found in bifidobacteria isolated from non-human primates, but not from the bifidobacteria of carnivores and honey-bee. On comparing species from different hosts, such as poultry and herbivorous/omnivorous non-primates, it would appear that folate production is characteristic of primate (human and non-human) bifidobacteria but not of non-primate. Isolates from orangutan and chimpanzee had a high total folate content, the mean values being 7792 μg/100 g dry matter (DM) for chimpanzee and 8368 μg/100 g DM for orangutan. The tetrahydrofolate (H4folate) and 5-methyl-tetrahydrofolate (5-CH3–H4folate) distribution varied in the bifidobacteria of the different animal species, but remained similar in the strains of the same species: B. dentium CHZ9 contained the least 5-CH3–H4folate (3749 μ/100 g DM), while B. adolescentis ORG10 contained the most (8210 μg/100 g DM). Our data suggest a correlation between phylogenetic lineage and capacity of folate production by bifidobacteria, rather than with dietary type of the host. Research article Gut microbiota role in dietary protein metabolism and health-related outcomes: The two sides of the coinTrends in Food Science & Technology, Volume 57, Part B, 2016, pp. 213-232 Show abstractNavigate Down Human gut bacteria can synthesize proteinogenic amino acids and produce a range of metabolites via protein fermentation, some known to exert beneficial or harmful physiological effects on the host. However, the effects of the type and amount of dietary protein consumed on these metabolic processes, as well as the effects of the microbiota-derived amino acids and related metabolites on the host health are still predominantly unknown. This review provides an up-to-date description of the dominant pathways/genes involved in amino acid metabolism in gut bacteria, and provides an inventory of metabolic intermediates derived from bacterial protein fermentation that may affect human health. Advances in understanding bacterial protein fermentation pathways and metabolites generated at a global level via the implementation of ‘omics’ technologies are reviewed. Finally, the impact of dietary protein intake and high-protein diets on human health is discussed. The intestinal microbiota is able to synthesize amino acids, but the net result of amino acid production and utilization, according to dietary patterns still needs to be determined. The amount of ingested dietary protein appears to modify both the diversity and composition of the intestinal microbiota as well as the luminal environment of the intestinal epithelium and peripheral tissues. The understanding of the consequences of such changes on the host physiology and pathophysiology is still in an early stage but major progress is expected in the near future with the investigation of host-microbe omics profiles from well-controlled human intervention studies. |
Bacteria in the large intestine produce vitamin
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