El Niño Altered Gut Microbiota of Children: A New Insight on Weather-Gut Interactions and Protective Effects of Probiotic.

Changes in weather often trigger a myriad of negative impacts on the environment, which eventually affect human health. During the early months of 2016, Malaysia experienced El Niño, with an extremely dry season of almost zero rainfall. At the same time, an increase of more than twofold in fecal secretary immunoglobulin-A (SIgA) levels of healthy preschool children aged 2-6 years was observed, accompanied by an increase in phylum Bacteroidetes, predominantly attributed to genus Bacteroides and Odoribacter, which also positively correlated with fecal SIgA levels. Here, we present evidence to illustrate the detrimental effects of weather change on a microscopic "environment," the human gut ecosystem. We also discuss the protective effects of probiotic against dysbiosis as induced by weather change. The increase in Bacteroidetes was at an expense of decreased genus Faecalibacterium and Veillonella (phylum Firmicutes), whereas children consuming probiotic had a decrease in genus Collinsella, Atopobium, and Eggerthella (phylum Actinobacteria) instead.

Probiotic Bifidobacterium longum alters gut luminal metabolism through modification of the gut microbial community.

Probiotics are well known as health-promoting agents that modulate intestinal microbiota. However, the molecular mechanisms underlying this effect remain unclear. Using gnotobiotic mice harboring 15 strains of predominant human gut-derived microbiota (HGM), we investigated the effects of Bifidobacterium longum BB536 (BB536-HGM) supplementation on the gut luminal metabolism. Nuclear magnetic resonance (NMR)-based metabolomics showed significantly increased fecal levels of pimelate, a precursor of biotin, and butyrate in the BB536-HGM group. In addition, the bioassay revealed significantly elevated fecal levels of biotin in the BB536-HGM group. Metatranscriptomic analysis of fecal microbiota followed by an in vitro bioassay indicated that the elevated biotin level was due to an alteration in metabolism related to biotin synthesis by Bacteroides caccae in this mouse model. Furthermore, the proportion of Eubacterium rectale, a butyrate producer, was significantly higher in the BB536-HGM group than in the group without B. longum BB536 supplementation. Our findings help to elucidate the molecular basis underlying the effect of B. longum BB536 on the gut luminal metabolism through its interactions with the microbial community.

Clinical effects of probiotic Bifidobacterium longum BB536 on immune function and intestinal microbiota in elderly patients receiving enteral tube feeding.

BACKGROUND: Immune system function declines with age. We evaluated the effects of supplementation with the probiotic Bifidobacterium longum BB536 on immune function and intestinal microbiota in the elderly. MATERIALS AND METHODS: In a double-blind study, 45 elderly patients fed by enteral tube feeding (mean [SD] age 81.7 [8.7] years) were given BB536 (n = 23) or a placebo powder (n = 22) for 12 weeks and were observed for an additional 4 weeks posttreatment. At week 4, all patients received an influenza vaccination (A/H1N1, A/H3N2, and B). Clinical data were assessed, including body temperature, bowel movements, fecal microbiota, and immunological biomarkers in blood. RESULTS: BB536 intake significantly increased cell numbers of bifidobacteria in fecal microbiota. There was a tendency toward an increase (P = .085 at week 4 and P = .070 at week 16) of serum IgA in the BB536 group compared with the placebo group. BB536 intake did not significantly affect hemagglutination inhibition (HI) titers in response to the influenza vaccine. Natural killer (NK) cell activity decreased significantly in the placebo group during the intervention but not in the BB536 group. Among those subjects with low NK cell activity (<55%, n = 10 for each group), a significant intergroup difference (P < .05) was observed in the changed values from baseline of NK cell activity at weeks 8 and 12. CONCLUSIONS: These results shed new light on the potential of long-term ingestion of BB536 in increasing the cell number of bifidobacteria in intestinal microbiota and modulating immune function in the elderly.

Changes in plasma TARC levels during Japanese cedar pollen season and relationships with symptom development.

BACKGROUND: Japanese cedar pollinosis (JCPsis) is an immunoglobulin E-mediated type I allergy caused by exposure to Japanese cedar pollen (JCP). Blood thymus and activation-regulated chemokine (TARC) levels are well known as an objective parameter for disease severity for several allergic disorders. The present study aims to evaluate the relationship between TARC levels and disease symptoms during the pollen season. METHODS: Analysis was performed of results of symptom scores and blood parameters obtained from 42 JCPsis patients who participated in a probiotic (Bifidobacterium longum BB536) intake trial in the JCP season of 2005 (January to April), using a randomized, double-blind, placebo-controlled design. RESULTS: Significant increases in plasma TARC levels were observed in subjects receiving placebo (p < 0.05 in February and p < 0.01 in March), but not in subjects receiving BB536. Increased plasma TARC levels were markedly greater in subjects who experienced severe symptoms and were thus excluded early from the intervention (placebo group: n = 8; BB536 group: n = 2). Significant differences were found in changes from baseline TARC levels in February and March between the subjects where treatment was terminated early and the remaining ones. Among the remaining subjects, significant positive correlations were found as regards changed values of TARC compared to baseline in March and April with symptom scores recorded in the pollen season. CONCLUSION: Changed values of blood TARC in the pollen season may offer promising parameters for assessing disease severity and monitoring treatment.

Clinical efficacy of probiotic Bifidobacterium longum for the treatment of symptoms of Japanese cedar pollen allergy in subjects evaluated in an environmental exposure unit.

BACKGROUND: Japanese cedar pollinosis (JCPsis) affects nearly one in six Japanese. Oral administration of Bifidobacterium longum BB536 has been shown to be effective in relieving JCPsis symptoms during the pollen season. METHODS: This double- two-way crossover study was designed to evaluate the efficacy of BB536 on reducing symptoms in JCPsis patients exposed to Japanese cedar pollen (JCP) in an environmental exposure unit (EEU) outside of the normal JCP season. After a 1-week run-in period, subjects (n=24) were randomly allocated to receive BB536 powder (approximately 5x1010) or placebo twice a day for 4 weeks. After a 2-week washout period, subjects were crossed over to another 4 weeks of intake. At the end of each intake period, subjects received controlled JCP exposure for 4 hours in the EEU. Symptoms were self-rated 30 minutes before and every 30 minutes during the exposures. From the first day of exposure through the next 5 successive days, participants self-rated their delayed symptoms and medication uses. Blood samples were taken before the exposures. The mean JCP levels for exposures were 6500 to 7000 grains/m3 air. RESULTS: In comparison with placebo, BB536 intake significantly reduced the ocular symptom scores during JCP exposures. Evaluating delayed symptoms after exposures indicated that scores for disruption of normal activities were significantly lower in the BB536 group compared with the placebo group. Prevalence of medication use was markedly reduced by BB536 intake. CONCLUSIONS: These results suggest the potential beneficial effect of BB536 in relieving symptoms of JCP allergy.

Effect of partially hydrolyzed guar gum (PHGG) on the bioaccessibility of fat and cholesterol.

The addition of a compound that lowers the intestinal uptake of fat and cholesterol might be an interesting strategy to reduce the risk of vascular disease. Partially hydrolyzed guar gum (PHGG) has been shown to have this effect in healthy volunteers after intake of a yogurt drink with 3 to 6% PHGG. In the present study a yogurt drink with 3% sunflower oil and 4% egg yolk was tested with 3% and 6% PHGG, and compared to a control without PHGG. Experiments were performed in a multi-compartmental model of the gastrointestinal tract, equipped to study the digestion and availability for absorption (bioaccessibility) of lipids. The results show that PHGG decreases the bioaccessibility of both fat and cholesterol in a dose-dependent manner. The bioaccessibility of fat was 79.4+/-1.7%, 70.8+/-2.5% and 60.1+/-1.1% for the control experiments and the experiments with 3% and 6% PHGG respectively. The bioaccessibility of cholesterol was 82.2+/-2.0%, 75.4+/-1.2% and 64.0+/-4.3% for the control and the experiments with 3% and 6% PHGG respectively. Additional experiments indicated that PHGG reduces bioaccessibility through the depletion flocculation mechanism. Depletion flocculation antagonizes the emulsification by bile salts and thus decreases lipolytic activity, resulting in a lower bioaccessibility of fat and cholesterol. Depletion flocculation with polymers might be an interesting mechanism, not described before, to reduce fat and cholesterol absorption.