B. adolescentis ameliorates chronic colitis by regulating Treg/Th2 response and gut microbiota remodeling.

Inflammatory bowel disease (IBD) is defined as an immune dysregulation disease with poor prognosis. Various therapies based on gut microbe modulation have been proposed. In this study, we aim to explore the therapeutic effect of B. adolescentis on IBD, as well as the immune and microecology mechanism of B. adolescentis in IBD. The fecal level of B. adolescentis was decreased in the IBD patients compared with the normal people in our cohort and the GMrepo database. To further clarify the role of B. adolescentis in IBD, we induced chronic colitis with three cycles of dextran sulfate sodium (DSS). We found B. adolescentis gavage exhibited protective effects as evidenced by the significantly decreased diarrhea score, spleen weight, and increased colon length. Accordingly, the cumulative histological grading was decreased in the B. adolescentis administration group. In addition, tight junction protein and mucin family were enhanced after B. adolescentis treatment. Furthermore, distinct effects were found with decreased pro-inflammatory cytokines such as TNF-α, IL-6, IL-1ß, IL-18, IL-22, IL-9 and increased anti-inflammatory cytokines IL-10, IL-4, IL-5. Importantly, the colon lamina propria in the B. adolescentis group consisted of more Treg and Th2 cells, which inhibited extreme gut inflammation. Additionally, 16srRNA sequencing showed an evident increase in the B:F ratio in the B. adolescentis group. In particular, B. adolescentis application inhibited the excessive growth of Akkermansia and Escherichia-Shigella in genus level. In conclusion, B. adolescentis refined the DSS-induced chronic colitis by stimulating protective Treg/Th2 response and gut microbiota remodeling. B. adolescentis regularly treatment might improve the therapeutic effects for inflammatory bowel disease.

Study on the additive protective effect of PGLYRP3 and Bifidobacterium adolescentis Reuter 1963 on severity of DSS-induced colitis in Pglyrp3 knockout (Pglyrp3 -/-) and wild-type (WT) mice.

BACKGROUND AND AIMS: Pglyrp3 is a bactericidal innate immunity protein known to sustain the habitual gut microbiome and protect against experimental colitis. Intestinal inflammation and metaflammation are commonly associated with a marked reduction of commensal bifidobacteria. Whether Pglyrp3 and bifidobacteria interact synergistically or additively to alleviate metaflammation is unknown. We investigated the extent to which Pglyrp3 and bifidobacteria regulate metaflammation and gut bacterial dysbiosis in DSS-induced mouse models of intestinal inflammation. MATERIAL & METHODS: 8-10 weeks old male mice were used. In both WT and Pglyrp3 -/- experiments, the mice were randomly divided into three groups of 16 mice per group: (1) a control group receiving sterile tap water, (2) an experimental group receiving sterile tap water supplemented with only 5% DSS, and (3) an experimental group receiving sterile tap water supplemented with 5% DSS and 1 × 109 CFU/ml of Bifidobacterium adolescentis (B.a.) for 7 days. Wild-type (WT) littermates of the respective gene (i.e. Pglyrp3) were used as controls throughout the study. Clinical signs of general health and inflammation were monitored daily. Faecal pellet samples were analysed by qRT-PCR for microbial composition. Histology of relevant organs was carried out on day 8. Metabolic parameters and liver inflammation were determined in serum samples. RESULTS: Intestinal inflammation in mice of group 2 were significantly increased compared to those of control group 1. There was a significant difference in mean scores for inflammation severity between DSS-treated WT and DSS-treated Pglyrp3 -/- mice. Buildup of key serum metabolic markers (cholesterol, triglyceride and glucose) was set off by colonic inflammation. qRT-PCR quantification showed that DSS significantly decreased the Clostridium coccoides and Bifidobacterium cell counts while increasing those of Bacteroides group in both WT and Pglyrp3 -/- mice. These manifestations of DSS-induced dysbiosis were significantly attenuated by feeding B.a. Both the local and systemic ill-being of the mice alleviated when they received B.a. DISCUSSION: This study shows that Pglyrp3 facilitates recognition of bifidobacterial cell wall-derived peptidoglycan, thus leading additively to a reduction of metaflammation through an increase in the number of bifidobacteria, which were able to mitigate intestinal immunopathology in the context of Pglyrp3 blockade.

Bifidobacterium adolescentis and Lactobacillus rhamnosus alleviate non-alcoholic fatty liver disease induced by a high-fat, high-cholesterol diet through modulation of different gut microbiota-dependent pathways.

The incidence of non-alcoholic fatty liver disease (NAFLD) has increased year on year, and the increasing appreciation of the importance of gut microbiota provides novel therapeutic avenues for the treatment of NAFLD. To explore the similarities and differences between lactic acid bacteria (LAB) known to alleviate NAFLD, we selected three strains of Bifidobacterium adolescentis and three strains of Lactobacillus rhamnosus to administer to C57BL/6J mice on a high-fat, high-cholesterol diet (HFHCD) for 23 weeks. Subsequently, the effects of the LAB were evaluated through various measures. The six LAB strains were found to have varying degrees of efficacy in the prevention of NAFLD. We found that there were interspecific and intraspecific differences in the beneficial effects, mainly with respect to energy metabolism, lipid metabolism and short-chain fatty acid concentration. Three strains of B. adolescentis and one strain of L. rhamnosus were found to relieve NAFLD by increasing the concentration of short-chain fatty acids in the intestine of NAFLD mice. The other two strains of L. rhamnosus, LGG and L10-1, relieved NAFLD through different ways, LGG modulated energy metabolism and lipid metabolism, and L10-1 reduced liver inflammation. Examination of gut microbiota indicated that the six LAB strains could block the HFHCD-induced elevation of Firmicutes/Bacteroidetes and alter the dominant species within the gut. These results suggest that B. adolescentis and L. rhamnosus can inhibit the development of NAFLD by regulating gut microbiota, and their use is thus a promising therapeutic strategy.

Lactobacillus reuteri NK33 and Bifidobacterium adolescentis NK98 Alleviate Escherichia coli-Induced depression and Gut Dysbiosis in Mice.

Lactobacillus reuteri NK33 (NK33) and Bifidobacterium adolescentis NK98 (NK98) alleviate immobilization stress-induced depression. To understand the gut microbiota-mediated mechanisms of NK33 and NK98 against depression, we examined their effects on Escherichia coli K1 (K1)-induced depression and gut dysbiosis in mice. NK33, NK98, and their mixtures (1:1, 4:1, and 9:1) mitigated K1-induced depression and colitis. NK33 and NK98 additively or synergistically increased BDNF+/NeuN+ cell population and suppressed NF-κB action in the hippocampus. They alleviated gut dysbiosis by reducing the Proteobacteria population and increasing the Clostridia population. These results suggest that NK33 and NK98 may alleviate depression and colitis by ameliorating gut dysbiosis.

IL-10 Expression-Inducing Gut Bacteria Alleviate High-Fat Diet-Induced Obesity and Hyperlipidemia in Mice.

In the present study, we examined the effects of interleukin (IL)-10 expression-inducing bacteria Bifidobacterium adolescentis HP1, Lactobacillus mucosae HP2, and Weissella cibaria HP3 on high-fat diet (HFD)-induced obesity and liver steatosis in mice. Oral gavage of HP1, HP2, and HP3 reduced HFD-induced bodyweight gain, triglycerides, and total cholesterol levels in the blood and liver. They also suppressed HFD-induced colitis and the fecal δ,γ-Proteobacteria population. Of the tested bacteria, HP2, which most potently inhibited IL-10 expression, also suppressed HFD-induced bodyweight gain, liver steatosis, and colitis most effectively. These findings suggest that IL-10 expression-inducing gut bacteria can suppress obesity and liver steatosis.

Bifidobacterium adolescentis (DSM 20083) and Lactobacillus casei (Lafti L26-DSL): Probiotics Able to Block the In Vitro Adherence of Rotavirus in MA104 Cells.

Rotavirus is the leading worldwide cause of gastroenteritis in children under five years of age. Even though there are some available vaccines to prevent the disease, there are limited strategies for challenging diarrhea induced by rotavirus infection. For this reason, researchers are constantly searching for other approaches to control diarrhea by means of probiotics. In order to demonstrate the ability of some probiotic bacteria to interfere with the in vitro rotavirus infection in MA104 cells, strains of Lactobacillus sp. and Bifidobacterium sp. were tested in MA104 cells before the viral infection. As a preliminary assay, a blocking effect treatment was performed with viable bacteria. In this screening assay, four of initial ten bacteria showed a slight reduction of the viral infection (measured by percentage of infection). L. casei (Lafti L26-DSL), L. fermentum(ATCC 9338), B. adolescentis (DSM 20083), and B. bifidum (ATCC 11863) were used in further experiments. Three different treatments were tested in order to evaluate protein-based metabolites obtained from mentioned bacteria: (i) cell exposure to the protein-based metabolites before viral infection, (ii) exposure to protein-based metabolites after viral infection, and (iii) co-incubation of the virus and protein-based metabolites before viral infection to the cell culture. The best effect performed by protein-based metabolites was observed during the co-incubation assay of the virus and protein-based metabolites before adding them into the cell culture. The results showed 25 and 37% of infection in the presence of L. casei and B. adolescentis respectively. These results suggest that the antiviral effect may be occurring directly with the viral particle instead of making a blocking effect of the cellular receptors that are needed for the viral entrance.

Anxiolytic-like effect of Bifidobacterium adolescentis IM38 in mice with or without immobilisation stress.

To better understand the role of gut microbiota in the anxiety, we isolated bifidobacteria and lactobacilli from the human faecal microbiota, investigated their inhibitory effects on the expression of interleukin (IL)-6 and tumour necrosis factor (TNF)-α in lipopolysaccharide-stimulated macrophages, and examined the anxiolytic-like effect of Bifidobacterium adolescentis IM38 in mice treated with or without immobilisation stress using the elevated plus maze (EPM) task. Oral administration of IM38 at a dose of 1×109 cfu/mouse showed a significant anxiolytic-like effect both in mice exposed to immobilisation stress and in control mice using the EPM test (P<0.05). Moreover, IM38 treatment significantly increased the amount of time spent on open arms and open arm entries. The anxiolytic-like effect of IM38 was comparable to that of buspirone (1 mg/kg). Moreover, this anxiolytic-like effect was blocked by treatment with flumazenil (3 mg/kg, i.p.), a benzodiazepine receptor antagonist, but was not affected by treatment with bicuculine or WAY-100635. IM38 treatment also reduced the blood levels of corticosterone and IL-6 in mice with or without immobilisation stress, whereas this effect was abolished by treatment with flumazenil. IM38 treatment also reduced the blood TNF-α level in mice subjected to immobilisation stress but not in normal control mice. Treatment with flumazenil also significantly increased TNF-α and IL-6 levels in immobilisation stress-free mice treated with IM38. These findings suggest that IM38 may attenuate anxiety through modulation of the benzodiazepine site on the GABAA receptor and modulate stress-related cytokine expression.

Bifidobacterium adolescentis Exerts Strain-Specific Effects on Constipation Induced by Loperamide in BALB/c Mice.

Constipation is one of the most common gastrointestinal complaints worldwide. This study was performed to determine whether Bifidobacterium adolescentis exerts inter-strain differences in alleviating constipation induced by loperamide in BALB/c mice and to analyze the main reasons for these differences. BALB/c mice underwent gavage with B. adolescentis (CCFM 626, 667, and 669) once per day for 17 days. The primary outcome measures included related constipation indicators, and the secondary outcome measures were the basic biological characteristics of the strains, the concentration changes of short-chain fatty acids in feces, and the changes in the fecal flora. B. adolescentis CCFM 669 and 667 relieved constipation symptoms by adhering to intestinal epithelial cells, growing quickly in vitro and increasing the concentrations of propionic and butyric acids. The effect of B. adolescentis on the gut microbiota in mice with constipation was investigated via 16S rRNA metagenomic analysis. The results revealed that the relative abundance of Lactobacillus increased and the amount of Clostridium decreased in the B. adolescentis CCFM 669 and 667 treatment groups. In conclusion, B. adolescentis exhibits strain-specific effects in the alleviation of constipation, mostly due to the strains' growth rates, adhesive capacity and effects on the gut microbiome and microenvironment.