Explore the vast range of titles available.

Nutritional supplements are popular among athletes to improve performance and physical recovery. Protein supplements fulfill this function by improving performance and increasing muscle mass; however, their effect on other organs or systems is less well known. Diet alterations can induce gut microbiota imbalance, with beneficial or deleterious consequences for the host. To test this, we performed a randomized pilot study in cross-country runners whose diets were complemented with a protein supplement (whey isolate and beef hydrolysate) (n = 12) or maltodextrin (control) (n = 12) for 10 weeks. Microbiota, water content, pH, ammonia, and short-chain fatty acids (SCFAs) were analyzed in fecal samples, whereas malondialdehyde levels (oxidative stress marker) were determined in plasma and urine. Fecal pH, water content, ammonia, and SCFA concentrations did not change, indicating that protein supplementation did not increase the presence of these fermentation-derived metabolites. Similarly, it had no impact on plasma or urine malondialdehyde levels; however, it increased the abundance of the Bacteroidetes phylum and decreased the presence of health-related taxa including Roseburia, Blautia, and Bifidobacterium longum. Thus, long-term protein supplementation may have a negative impact on gut microbiota. Further research is needed to establish the impact of protein supplements on gut microbiota.

Resident gut bacteria can affect patient responses to cancer immunotherapy (see the Perspective by Jobin). Routy et al. show that antibiotic consumption is associated with poor response to immunotherapeutic PD-1 blockade. They profiled samples from patients with lung and kidney cancers and found that nonresponding patients had low levels of the bacterium Akkermansia muciniphila . Oral supplementation of the bacteria to antibiotic-treated mice restored the response to immunotherapy. Matson et al. and Gopalakrishnan et al. studied melanoma patients receiving PD-1 blockade and found a greater abundance of “good” bacteria in the guts of responding patients. Nonresponders had an imbalance in gut flora composition, which correlated with impaired immune cell activity. Thus, maintaining healthy gut flora could help patients combat cancer. Science , this issue p. 91 , p. 104 , p. 97 ; see also p. 32 Gut bacteria influence patient response to cancer therapy. Anti–PD-1–based immunotherapy has had a major impact on cancer treatment but has only benefited a subset of patients. Among the variables that could contribute to interpatient heterogeneity is differential composition of the patients’ microbiome, which has been shown to affect antitumor immunity and immunotherapy efficacy in preclinical mouse models. We analyzed baseline stool samples from metastatic melanoma patients before immunotherapy treatment, through an integration of 16 S ribosomal RNA gene sequencing, metagenomic shotgun sequencing, and quantitative polymerase chain reaction for selected bacteria. A significant association was observed between commensal microbial composition and clinical response. Bacterial species more abundant in responders included Bifidobacterium longum , Collinsella aerofaciens , and Enterococcus faecium. Reconstitution of germ-free mice with fecal material from responding patients could lead to improved tumor control, augmented T cell responses, and greater efficacy of anti–PD-L1 therapy. Our results suggest that the commensal microbiome may have a mechanistic impact on antitumor immunity in human cancer patients.

Accumulating evidence indicates that the gut microbiota communicates with the central nervous system, possibly through neural, endocrine, and immune pathways, and influences brain function. B. longum 1714™ has previously been shown to attenuate cortisol output and stress responses in healthy subjects exposed to an acute stressor. However, the ability of B. longum 1714™ to modulate brain function in humans is unclear. In a randomized, double-blinded, placebo-controlled trial, the effects of B. longum 1714™ on neural responses to social stress, induced by the \"Cyberball game,\" a standardized social stress paradigm, were studied. Forty healthy volunteers received either B. longum 1714™ or placebo for 4 weeks at a dose of 1 × 10 cfu/d. Brain activity was measured using magnetoencephalography and health status using the 36-item short-form health survey. B. longum 1714™ altered resting-state neural oscillations, with an increase in theta band power in the frontal and cingulate cortex (P < 0.05) and a decrease in beta-3 band in the hippocampus, fusiform, and temporal cortex (P < 0.05), both of which were associated with subjective vitality changes. All groups showed increased social stress after a 4-week intervention without an effect at behavioral level due to small sample numbers. However, only B. longum 1714™ altered neural oscillation after social stress, with increased theta and alpha band power in the frontal and cingulate cortex (P < 0.05) and supramarginal gyrus (P < 0.05). B. longum 1714™ modulated resting neural activity that correlated with enhanced vitality and reduced mental fatigue. Furthermore, B. longum 1714™ modulated neural responses during social stress, which may be involved in the activation of brain coping centers to counter-regulate negative emotions.

Lycopene rich food and dark chocolate are among the best-documented products with a broad health benefit. This study explored the systemic effect of lycopene and dark chocolate (DC) on gut microbiota, blood, liver metabolism, skeletal muscle tissue oxygenation and skin. 30 volunteers were recruited for this trial, 15 women and 15 men with a mean age of 55 ± 5.7 years and with moderate obesity, 30 < BMI < 35 kg/m2. They were randomized and divided into five equal interventional groups: three received different formulations of lycopene, one of them with a 7 mg daily dose and two with 30 mg; another group was given 10 g of DC with 7 mg lycopene embedded into its matrix, and the last group received 10 g DC. The trial was double-blinded for the three lycopene groups and separately for the 2 DC groups; the trial lasted for 1 month. By the end of the trial there were dose-dependent changes in the gut microbiota profile in all three lycopene groups with an increase of relative abundance of, e.g., Bifidobacterium adolescentis and Bifidobacterium longum. This was also accompanied by dose-dependent changes in the blood, liver metabolism, skeletal muscle and skin parameters. Consumption of DC resulted in increased relative abundance of, e.g., Lactobacillus and a reduction of corneocyte exfoliation. This is the first study which reports the prebiotic potential of lycopene and DC.

Type II arabinogalactan (AG) is a soluble prebiotic fiber stimulating the proliferation of bifidobacteria in the human gut. Larch AG, which is comprised of type II AG, is known to be utilized as an energy source for Bifidobacterium longum subsp. longum ( B. longum ). We have previously characterized GH43_24 exo-β-1,3-galactanase (Bl1,3Gal) for the degradation of type II AG main chains in B. longum JCM1217. In this study, we characterized GH30_5 exo-β-1,6-galactobiohydrolase (Bl1,6Gal) and GH43_22 α- l -arabinofuranosidase (BlArafA), which are degradative enzymes for type II AG side chains in cooperation with exo-β-1,3-galactanase. The recombinant exo-β-1,6-galactobiohydrolase specifically released β-1,6-galactobiose (β-1,6-Gal 2 ) from the nonreducing terminal of β-1,6-galactooligosaccharides, and the recombinant α- l -arabinofuranosidase released arabinofuranose (Ara f ) from α-1,3-Ara f -substituted β-1,6-galactooligosaccharides. β-1,6-Gal 2 was additively released from larch AG by the combined use of type II AG degradative enzymes, including Bl1,3Gal, Bl1,6Gal, and BlArafA. The gene cluster encoding the type II AG degradative enzymes is conserved in all B. longum strains, but not in other bifidobacterial species. The degradative enzymes for type II AG side chains are thought to be important for the acquisition of type II AG in B. longum .

Background The importance of the gut microbiota at the early stage of life and their longitudinal effect on host health have recently been well investigated. In particular, Bifidobacterium longum subsp. longum , a common component of infant gut microbiota, appears in the gut shortly after birth and can be detected there throughout an individual’s lifespan. However, it remains unclear whether this species colonizes in the gut over the long term from early infancy. Here, we investigated the long-term colonization of B . longum subsp. longum by comparing the genotypes of isolates obtained at different time points from individual subjects. Strains were isolated over time from the feces of 12 subjects followed from early infancy (the first six months of life) up to childhood (approximately six years of age). We also considered whether the strains were transmitted from their mothers’ perinatal samples (prenatal feces and postnatal breast milk). Results Intra-species diversity of B. longum subsp. longum was observed in some subjects’ fecal samples collected in early infancy and childhood, as well as in the prenatal fecal samples of their mothers. Among the highlighted strains, several were confirmed to colonize and persist in single individuals from as early as 90 days of age for more than six years; these were classified as long-term colonizers. One of the long-term colonizers was also detected from the corresponding mother’s postnatal breast milk. Quantitative polymerase chain reaction data suggested that these long-term colonizers persisted in the subjects’ gut despite the existence of the other predominant species of Bifidobacterium . Conclusions Our results showed that several strains belonging to B. longum subsp. longum colonized in the human gut from early infancy through more than six years, confirming the existence of long-term colonizers from this period. Moreover, the results suggested that these strains persisted in the subjects’ gut while co-existing with the other predominant bifidobacterial species. Our findings also suggested the importance of microbial-strain colonization in early infancy relative to their succession and showed the possibility that probiotics targeting infants might have longitudinal effects. Trial Registration TRN: ISRCTN25216339 . Date of registration: 11/03/2016. Prospectively registered.

PurposeOrange juice (OJ) flavanones undergo limited absorption in the upper gastrointestinal tract and reach the colon where they are transformed by the microbiota prior to absorption. This study investigated the ability of two probiotic bacteria, Bifidobacterium longum R0175 and Lactobacillus rhamnosus subsp. Rhamnosus NCTC 10302 to catabolise OJ flavanones.MethodsThe bacteria were incubated with hesperetin-7-O-rutinoside, naringenin-7-O-rutinoside, hesperetin and naringenin, and the culture medium and intracellular cell extracts were collected at intervals over a 48 h of incubation period. The flavanones and their phenolic acid catabolites were identified and quantified by HPLC–HR–MS.ResultsBoth probiotics were able to subject hesperetin to ring fission yielding 3-(3′-hydroxy-4′-methoxyphenyl)propionic acid which was subsequently demethylated producing 3-(3′,4′-dihydroxyphenyl)propionic acid and then via successive dehydroxylations converted to 3-(3′-hydroxyphenyl)propionic acid and 3-(phenyl)propionic acid. Incubation of both bacteria with naringenin resulted in its conversion to 3-(4′-hydroxyphenyl)propionic acid which underwent dehydroxylation yielding 3-(phenyl)propionic acid. In addition, only L. rhamnosus exhibited rhamnosidase and glucosidase activity and unlike B. longum, which was able to convert hesperetin-7-O-rutinoside and naringenin-7-O-rutinoside to their respective aglycones. The aglycones were then subjected to ring fission and further catabolised in a similar manner to that described above. The flavanones and their catabolites were found in the culture medium but not accumulated in the bacterial cells.ConclusionsThese findings demonstrate the enzymatic potential of single strains of bifidobacterium and lactobacillus which may be involved in the colonic catabolism of OJ flavanones in vivo.

Background It is evident that various drugs influence the gut microbiota, yet the precise mechanism driving these effects remain ambiguous. Considering the growing recognition of gut microbiota’s role in health and disease, it is important to explore how commonly used drugs, such as antihistamines, may alter microbial composition and function. Histamine, an essential interkingdom signaling molecule, shapes bacterial virulence, biofilm formation, and immune regulation. However, the effects of antihistamines on bacterial colonization are mostly unknown. This study aimed to investigate the potential effects of antihistamine exposure on critical factors which affect the pathogenicity and colonization of selected gut bacterial species, such as growth, biofilm formation, and adherence to cell lines, at intestinal concentrations. If antihistamines influence bacterial metabolism or composition, they may consequently affect Short Chain Fatty Acid (SCFA) production, which could have downstream effects on gut homeostasis and immune function. Specifically, we examined the impact of three antihistamines – fexofenadine HCl, cyproheptadine HCl, and desloratadine –on bacteria from the four dominant gut phyla: Bifidobacterium longum , Limosilactobacillus reuteri , Bacteroides fragilis , and Escherichia coli . Results Our results showed that cyproheptadine HCl and desloratadine inhibited the growth of all tested bacteria, whereas fexofenadine HCl promoted the growth of all species except B. longum . Furthermore, cyproheptadine HCl and desloratadine reduced the biofilm-forming capacity of these bacterial species and altered their effects on adherence to Caco-2/HT-29 cell lines aligning with changes in cell surface hydrophobicity: increased cell surface hydrophobicity correlated with greater bacterial adherence to surfaces. In contrast, fexofenadine HCl enhanced biofilm formation and adherence of B. longum and L. reuterii in Caco-2/HT-29 co-cultures. It also led to increased production of lactic and propionic acids, with a statistically significant increase observed in acetic acid levels ( p  < 0.05). Conclusion In summary, our findings suggest that fexofenadine HCl, unlike cyproheptadine HCl and desloratadine, supports the growth, and colonization of probiotic bacteria such as L. reuteri and B. longum with potential anti allergic benefits, and enhancing their SCFA production. Conversely, cyproheptadine HCl and desloratadine suppressed bacterial growth, hinting at potential antimicrobial properties that may warrant exploration for drug repurposing.

The treatment of coronavirus disease (COVID-19) and COVID-19-associated diarrhea remains challenging. This study aimed to evaluate the efficacy of a multi-strain probiotic in the treatment of COVID-19. This was a randomized, controlled, single-center, open-label trial (NCT04854941). Inpatients with confirmed COVID-19 and pneumonia were randomly assigned to a group that received a multi-strain probiotic (PRO group) or to the control group (CON group). There were 99 and 101 patients in the PRO and CON groups, respectively. No significant differences in mortality, total duration of disease and hospital stay, incidence of intensive care unit admission, need for mechanical ventilation or oxygen support, liver injury development, and changes in inflammatory biomarker levels were observed between the PRO and CON groups among all included patients as well as among subgroups delineated based on age younger or older than 65 years, and subgroups with chronic cardiovascular diseases and diabetes. Diarrhea on admission was observed in 11.5% of patients; it resolved earlier in the PRO group than in the CON group (2 [1–4] vs. 4 [3–6] days; p  = 0.049). Hospital-acquired diarrhea developed less frequently in the PRO group than in the CON group among patients who received a single antibiotic (0% vs. 12.5%; p  = 0.023) unlike among those who received > 1 antibiotic (10.5% vs. 13.3%; p  = 0.696). The studied probiotic had no significant effect on mortality and changes in most biomarkers in COVID-19. However, it was effective in treating diarrhea associated with COVID-19 and in preventing hospital-acquired diarrhea in patients who received a single antibiotic.

BackgroundInfant gut dysbiosis, often associated with low abundance of bifidobacteria, is linked to impaired immune development and inflammation—a risk factor for increased incidence of several childhood diseases. We investigated the impact of B. infantis EVC001 colonization on enteric inflammation in a subset of exclusively breastfed term infants from a larger clinical study.MethodsStool samples (n = 120) were collected from infants randomly selected to receive either 1.8 × 1010 CFU B. infantis EVC001 daily for 21 days (EVC001) or breast milk alone (controls), starting at day 7 postnatal. The fecal microbiome was analyzed using 16S ribosomal RNA, proinflammatory cytokines using multiplexed immunoassay, and fecal calprotectin using ELISA at three time points: days 6 (Baseline), 40, and 60 postnatal.ResultsFecal calprotectin concentration negatively correlated with Bifidobacterium abundance (P < 0.0001; ρ = −0.72), and proinflammatory cytokines correlated with Clostridiaceae and Enterobacteriaceae, yet negatively correlated with Bifidobacteriaceae abundance. Proinflammatory cytokines were significantly lower in EVC001-fed infants on days 40 and 60 postnatally compared to baseline and compared to control infants.ConclusionOur findings indicate that gut dysbiosis (absence of B. infantis) is associated with increased intestinal inflammation. Early addition of EVC001 to diet represents a novel strategy to prevent enteric inflammation during a critical developmental phase.