Probiotic Bifidobacterium bifidum G9-1 attenuates 5-fluorouracil-induced intestinal mucositis in mice via suppression of dysbiosis-related secondary inflammatory responses.

Bifidobacterium, a major component of the intestinal microbiota, has been clinically used for the treatment of diarrhoea and constipation. 5-Fluorouracil (5-FU), widely used for cancer chemotherapy, is known to frequently induce intestinal mucositis accompanied by severe diarrhoea. The present study examined the effect of Bifidobacterium bifidum G9-1 (BBG9-1) on 5-FU-induced intestinal mucositis in mice. Intestinal mucositis was induced by repeated administration of 5-FU for 6 days. BBG9-1 was administered orally once daily for 9 days, beginning 3 days before the onset of 5-FU treatment. Repeated administration of 5-FU caused severe intestinal mucositis, characterised by shortening of villi and destruction of crypts, accompanied by increases in intestinal myeloperoxidase activity and inflammatory cytokine expression, body weight loss, and diarrhoea on day 6. Daily administration of BBG9-1 significantly reduced the severity of intestinal mucositis and inflammatory responses and tended to attenuate clinical symptoms. In contrast, BBG9-1 failed to prevent apoptosis induction on day 1 after the first 5-FU administration. The structure of the intestinal microbiota, as analysed by weighted UniFrac distance, was largely altered by 5-FU treatment, but this change was mitigated by daily administration of BBG9-1. Moreover, 5-FU treatment decreased the abundance of Firmicutes and increased the abundance of Bacteroidetes, but these responses were also significantly inhibited by daily administration of BBG9-1. These results suggest that BBG9-1 has an ameliorative effect against 5-FU-induced intestinal mucositis through the attenuation of inflammatory responses via improve dysbiosis. BBG9-1 could be useful for the prevention of intestinal mucositis during cancer chemotherapy.

Apoptosis, Dysbiosis and Expression of Inflammatory Cytokines are Sequential Events in the Development of 5-Fluorouracil-Induced Intestinal Mucositis in Mice.

The chemotherapeutic agent 5-fluorouracil (5-FU) causes intestinal mucositis with severe diarrhoea, but the pathogenesis is not fully understood. In this study, we investigated the pathogenic effects of 5-FU in mice, focusing on apoptosis, enterobacteria and inflammatory cytokines. Repeated administration of 5-FU caused severe intestinal mucositis on day 6, accompanied by diarrhoea and body-weight loss. TNF-α expression increased 1 day after exposure to the drug, and spiked a second time on day 4, at which point myeloperoxidase activity and IL-1ß expression also increased. Apoptotic cells were observed in intestinal crypts only on day 1. 5-FU also induced dysbiosis, notably decreasing the abundance of intestinal Firmicutes while increasing the abundance of Bacteroidetes and Verrucomicrobia. Twice-daily co-administration of oral antibiotics significantly reduced the severity of intestinal mucositis and dysbiosis, and blocked the increase in myeloperoxidase activity and cytokine expression on day 6, without affecting apoptosis and TNF-α up-regulation on day 1. In cultured colonic epithelial cells, exposure to 5-FU also up-regulated TNF-α expression. Collectively, the data suggest that crypt apoptosis, dysbiosis and expression of inflammatory cytokines are sequential events in the development of intestinal mucositis after exposure to 5-FU. In particular, 5-FU appears to directly induce apoptosis via TNF-α and to suppress intestinal cell proliferation, thereby resulting in degradation of the epithelial barrier, as well as in secondary inflammation mediated by inflammatory cytokines.

Oral administration of Bifidobacterium bifidum G9-1 alleviates rotavirus gastroenteritis through regulation of intestinal homeostasis by inducing mucosal protective factors.

Human rotavirus (RV) infection is a leading cause of dehydrating diarrhea in infants and young children worldwide. Since therapeutic approaches to RV gastroenteritis are limited to alleviation of dehydration with oral rehydration solutions, more direct approaches to palliate symptoms of RV gastroenteritis are required. Treatments with probiotics have been increasingly recognized as alternative safe and low cost treatments for moderate infectious diarrhea. In this study, Bifidobacterium bifidum G9-1 (BBG9-1), which has been used as an intestinal drug for several decades, was shown to have a remarkable protective effect against RV gastroenteritis in a suckling mice model. As well as prophylactic oral administration of BBG9-1 from 2 days before RV infection, therapeutic oral administration of BBG9-1 from 1 day after RV infection significantly alleviated RV-induced diarrhea. Therapeutic administration of BBG9-1 reduced various types of damage in the small intestine, such as epithelial vacuolization and villous shortening, and significantly diminished the infectious RV titer in mixtures of cecal contents and feces. It was also shown that therapeutic administration of BBG9-1 significantly increased the number of acidic mucin-positive goblet cells and the gene expression of mucosal protective factors including MUC2, MUC3, MUC4, TGFß1 and TFF3 in the small intestine. This led to alleviation of low gut permeability shown as decreased gene expression levels of occludin, claudin-1 and villin-1 after RV infection. Furthermore, in the small intestine, therapeutic administration of BBG9-1 significantly palliated the decreased gene expression of SGLT-1, which plays an important role in water absorption. In the large intestine, administered BBG9-1 was shown to replicate to assimilate undigested nutrients, resulting in normalization of the abnormally high osmotic pressure. These results suggested that water malabsorption caused by RV infection was alleviated in mice administered BBG9-1. Thus, the present study showed that oral administration of BBG9-1 palliated diarrhea partly through protection against RV-induced lesions by inducing mucosal protective factors. Oral administration of BBG9-1 is thought to be an efficient method for management of an RV epidemic for both prophylactic and therapeutic purposes.

Actions of probiotics on trinitrobenzenesulfonic acid-induced colitis in rats.

We investigated the actions of probiotics, Streptococcus faecalis 129 BIO 3B (SF3B), in a trinitrobenzenesulfonic acid- (TNBS-) induced colitis model in rats. After TNBS was administered into the colons of rats for induction of colitis, the rats were divided into two groups: one group was given a control diet and the other group was given a diet containing SF3B for 14 days. There were no apparent differences in body weight, diarrhea period, macroscopic colitis score, and colonic weight/length ratio between the control group and SF3B group, suggesting that induction of colitis was not prevented by SF3B. Next, we investigated whether SF3B-containing diet intake affects the restoration of enteric neurotransmissions being damaged during induction of colitis by TNBS using isolated colonic preparations. Recovery of the nitrergic component was greater in the SF3B group than in the control group. A compensatory appearance of nontachykininergic and noncholinergic excitatory components was less in the SF3B group than in the control group. In conclusion, the present study suggests that SF3B-containing diet intake can partially prevent disruptions of enteric neurotransmissions induced after onset of TNBS-induced colitis, suggesting that SF3B has therapeutic potential.

Identification of Human Intestinal Microbiota of 92 Men by Data Mining for 5 Characteristics, i.e., Age, BMI, Smoking Habit, Cessation Period of Previous Smokers and Drinking Habit.

The intestinal microbiota compositions of 92 men living in Japan were identified following consumption of identical meals for 3 days. Fecal samples were analyzed by terminal restriction fragment length polymorphism with 4 primer-restriction enzyme systems, and the 120 obtained operational taxonomic units (OTUs) were analyzed by Data mining software focusing on the following 5 characteristics, namely, age, body mass index, present smoking habit, cessation period of previous smokers and drinking habit, according to the answers of the subjects. After performing Data mining analyses with each characteristic, the details of the constructed Decision trees precisely identified the subjects or discriminated them into various suitable groups. Through the pathways to reach the groups, practical roles of the related OTUs and their quantities were clearly recognized. Compared with the other identification methods for OTUs such as bicluster analyses, correlation coefficients and principal component analyses, the clear difference of this Data mining technique was that it set aside most OTUs and emphasized only some closely related ones. For example for a selected characteristic, such as smoking habit, only 7 OTUs out of 120 were able to identify all smokers, and the remaining 113 OTUs were thought of as data noise for smoking. Data mining analyses were affirmed as an effective method of subject discrimination for various physiological constitutions. The species of bacteria that were closely related to heavy smokers, i.e., HaeIII-291, were also discussed.

Effects of Bifidobacterium bifidum G9-1 on Nasal Symptoms in a Guinea Pig Model of Experimental Allergic Rhinitis.

Recent studies of several animal models have shown beneficial effects of probiotics against allergic responses. However, few reports have examined the effects of probiotics on allergic nasal symptoms such as sneezing and nasal obstruction in animal models of allergic rhinitis. This study evaluated the efficacy of Bifidobacterium bifidum G9-1 (BBG9-1) on antigen-induced nasal symptoms using guinea pig models of allergic rhinitis. Oral administration of BBG9-1 significantly inhibited antigen-induced allergic nasal reactions such as sneezing and nasal obstruction. Our results suggest that BBG9-1 may be useful for alleviating nasal symptoms in patients with allergic rhinitis.

Oral administration of Bifidobacterium bifidum G9-1 suppresses total and antigen specific immunoglobulin E production in mice.

Recent studies have suggested that oral bacteriotherapy with probiotics might be useful in the management of allergic diseases. We investigated the effect of oral administration of Bifidobacterium bifidum G9-1 (BBG9-1) on immunoglobulin (Ig) E production in BALB/c mice. Live BBG9-1 was orally administered to mice for 2 weeks from 1 week before ovalbumin (OVA)-immunization. The treatment of BBG9-1 significantly reduced serum total IgE level. In addition, BBG9-1 significantly and largely reduced the serum level of OVA-specific IgE without lowering of the specific IgG1 and increasing of the specific IgG2a. We also examined T helper type (Th) 1 and Th2 cytokine production from OVA-immunized splenocytes by restimulation with OVA in vitro. Productions of interferon (IFN)-gamma, interleukin (IL)-4 and IL-5 from the splenocytes of mice given BBG9-1 were weaker than those of control mice. We conclude that oral administration of BBG9-1 selectively and powerfully suppresses total and antigen specific IgE production in mice. It is suggested that BBG9-1 is useful for the prophylactic treatment in IgE-dependent allergic diseases.