Individuals in a community who developed irritable bowel syndrome (IBS) after major floods have significant mental health impairment. We aimed to determine if Bifidobacterium infantis M-63 was effective in improving symptoms, psychology and quality of life measures in flood-affected individuals with IBS and if the improvement was mediated by gut microbiota changes. Design was non-randomised, open-label, controlled before-and-after. Of 53 participants, 20 with IBS were given B. infantis M-63 (1x10(9) cfu/sachet/day) for three months and 33 were controls. IBS symptom severity scale, hospital anxiety and depression scale, SF-36 Questionnaire, hydrogen breath testing for small intestinal bacterial overgrowth and stools for 16S rRNA metagenomic analysis were performed before and after intervention. 11 of 20 who were given probiotics (M-63) and 20 of 33 controls completed study as per-protocol. Mental well-being was improved with M-63 vs controls for full analysis (P=0.03) and per-protocol (P=0.01) populations. Within-group differences were observed for anxiety and bodily pain (both P=0.04) in the M-63 per-protocol population. Lower ratio of Firmicutes/Bacteroidetes was observed with M-63 vs controls (P=0.01) and the lower ratio was correlated with higher post-intervention mental score (P=0.04). B. infantis M-63 is probably effective in improving mental health of victims who developed IBS after floods and this is maybe due to restoration of microbial balance and the gut-brain axis. However, our conclusion must be interpreted within the context of limited sample size.
Recombinant lactic acid bacteria (LAB), especially Lactococcus lactis, have been genetically engineered to express heterogeneous invasion proteins, such as the fibronectin binding protein A (FnBPA) from Staphylococcus aureus, to increase the invasion ability of the host strains, indicating a promising approach for DNA vaccine delivery. The presence of FnBPA has been also shown to be an adjuvant for co-delivered antigens, however, the underlying mechanisms are still not clear. To explore the above underlying mechanisms, in this study, we constructed a novel Lactobacillus plantarum strain with surface displayed FnBPA, which could significantly improve the adhesion and invasion ratios of L. plantarum strain on a porcine intestinal epithelial cell line (IPEC-J2) about two-fold compared with the empty vector. At the same time, the presence of FnBPA significantly stimulated the differentiation of bone marrow-derived dendritic cells (DCs) and increased the secretion of interleukin (IL)-6 and mRNA level of IL-6 gene, which were proved by flow cytometry, enzyme-linked immunosorbent assay (ELISA) and quantitative reverse transcription PCR (qRT-PCR). With regard to in vivo study, the presence of FnBPA significantly stimulated the differentiation of DCs in the Peyer's patch (PP) and the percentages of IL-4(+) and IL-17A(+) T helper (Th) cells of splenocytes in flow cytometry assay. In consistent with these results, the levels of IL-4 and IL-17A in serum as measured via ELISA also increased in mice treated with FnBPA(+) L. plantarum. Finally, the FnBPA strain increased the production of B220(+) B cells in mesenteric lymph node (MLN) and PP and the levels of FnBPA-specific IgG and sIgA antibodies, indicating the its possible application in vaccine field. This study demonstrated that the invasive L. plantarum with surface displayed FnBPA could modulate host immune response by stimulating the differentiation of DCs and Th cells which could possibly be responsive for the adjuvant effects of FnBPA.
Intestinal mucositis is a frequent side effect in cancer patients who are treated with chemotherapy. There are no effective treatment strategies to date. To find a novel way to alleviate mucositis, the effects of selenium-enriched Bifidobacterium longum (Se-B. longum) in preventing irinotecan (CPT-11)-induced intestinal mucositis in a mouse model were investigated. We tested the ability of Se-B. longum (Se 0.6 mg/kg, 5x10(8) cfu/mice) to reduce small intestinal mucositis induced by CPT-11 (75 mg/kg, daily) injected intraperitoneally for four consecutive days in mice. Se-B. longum significantly decreased mortality induced by CPT-11 from 71.4% to 16.7%. CPT-11 induced body weight loss, which was alleviated by preventative and simultaneous administration of Se-B. longum. Se-B. longum significantly decreased the severity of diarrhoea from 11 to 4% compared to the CPT-11 group. Inflammation, including intestinal shortening and upregulation of tumour necrosis factor-a and interleukin-1 beta induced by CPT-11, were prevented by Se-B. longum. Se-B. longum is effective in preventing small intestinal mucositis induced by CPT-11 and therefore has potential to be used clinically by cancer patients.
Human inflammatory bowel disease (IBD) and experimental colitis models in mice are associated with shifts in gut microbiota composition, and several probiotics are widely used to improve gastrointestinal health. Here, we investigated whether the probiotic Bacillus licheniformis Zhengchangsheng (R) (BL) ameliorates dextran sulphate sodium (DSS)-induced colitis through alteration of the gut microbiota. Experimental colitis was induced in BALB/C mice by dissolving 3% DSS in their drinking water for 7 days, which were gavaged with 0.2 ml phosphate-buffered saline or BL (3x10(7) cfu/ml) once a day. Administration of BL attenuated several effects of DSS-induced colitis, including weight loss, increased disease activity index, and disrupted intestinal barrier integrity. In addition, BL mitigated the reduction in faecal microbiota richness in DSS treated mice. Interestingly, BL was found to reduce the elevated circulating endotoxin level in mice with colitis by modulating the microbial composition of the microbiota, and this was highly associated with a proportional decrease in gut Bacteroidetes. Our results demonstrate that BL can attenuate DSS-induced colitis and provide valuable insight into microbiota interactions during IBD.
The improving-intestinal-microbial-balance properties of lactic acid bacteria (LAB) are well known. Thus, LAB could play a vital role in the pathogenesis of liver diseases. In the present study, 107 LAB strains were isolated from Mongolian camel milk products and identified to species, then screened for their probiotic properties. As a result, we identified 71 Lactobacillus bacteria belonging to 9 different species, and 36 Lactococcus bacteria belonging to 8 different species. Among them, six strains of LAB with strong tolerance and adhesion ability were further studied for their protective effect on acute liver injury induced by lipopolysaccharide (LPS)/D-galactosamine (D-GalN). These six strains of LAB were fed to mice for 7 weeks, and on the final day of the experiment, LPS/D-GalN were used to induce acute liver injury. After challenging, the degree of liver pathological changes, secretion of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in serum and liver, and the expression of tumour necrosis factor (TNF)-alpha and interleukin (IL)-6 in the liver and intestines were observed and quantified. The results showed that the degree of liver pathological changes in mice fed with the six LAB strains were relieved to varying degrees compared with the LPS/D-GalN-induced model group, and the expressions of AST, ALT, IL-6, and TNF-alpha factor were also significantly decreased. Moreover, the expression levels of these factors in mice pretreated with Lactobacillus paracasei subsp. paracasei WXD5 were significantly decreased compared with other experimental groups. This suggests the probiotic potential and pharmacological value of L. paracasei subsp. paracasei as a liver injury inhibitor in the intervention of inflammation-based liver disease.
Bacillus coagulans is a probiotic bacterium that produces spores. Due to its excellent stability, it has been widely used in medicine, food and chemical industry. Recent studies have shown that B. coagulans has therapeutic effects on intestinal diseases, such as acute diarrhoea, irritable bowel syndrome, antibiotic-related diarrhoea, constipation and colitis via modulation of the microbiota composition, host immunity and metabolism. Additionally, toxicological experiments and a large number of clinical observations have showed that B. coagulans is safe and has no effect of mutagenicity, teratogenicity or genotoxicity. This review summarises the latest advances associated with B. coagulans, from its biological features, probable action mechanisms, toxicity, and medical applications.
Formula-fed infants are more susceptible to infectious diseases because they lack the maternal immune factors transferred from breast milk, while their own immune system is still immature. As timely probiotic administration was suggested to promote immune system development in formula-fed infants, this study aimed at assessing the safety and the effects of a probiotic supplement (Bifidobacterium infantis R0033, Bifidobacterium bifidum R0071, and Lactobacillus helveticus R0052) on mucosal immune competence and digestive function in formula-fed infants. Healthy infants (3.5-6 months old) were randomised to receive either probiotic- (n=66) or placebo-supplemented (n=66) formula once a day for four weeks. In the probiotics group, faecal secretory immunoglobulin A (SIgA) levels remained similar between visit 2 (baseline; V2) and visit 3 (end-of-treatment; V3), but decreased in the placebo group. Changes in SIgA levels following treatment (log(10)Delta V3-V2 [95%CI]) between the probiotic and placebo groups were statistically significant (23 ng/dl [-57;102] and -137 ng/dl [-212;-62], respectively (P=0.0044; ANCOVA)). While log(10)Delta V3-V2 [95%CI] for salivary SIgA levels increased in both groups, this trend was more pronounced in the probiotics than in the placebo group with an increase of 123 ng/dl [9;236] and 37 ng/dL [-72;147], respectively (P=0.2829; ANCOVA). The weekly average number of stools/day was significantly higher in the probiotics group compared to placebo during the last week of treatment for the per protocol population. There was no difference in microbiota composition or anthropometric parameters between groups. No serious adverse event was reported, and all adverse events were mild and unrelated to the product or study. Our results show that formula-fed infants receiving probiotics maintained higher faecal SIgA levels at the end of the four-week treatment period, suggesting a positive effect of probiotics on SIgA production. This study demonstrates the safety of this probiotic formulation in infants. Formula-fed infants may benefit from probiotics supplementation to sustain the development of mucosal immunity.
Constipation has a significant influence on quality of life. Patients with constipation have slow waves in their gastrointestinal smooth muscles and less faecal water contents, which are closely associated with down-regulation of the interstitial cells of Cajal (ICC) in the gastrointestinal muscles and the aquaporin protein AQP3 expressed in colon epithelial cells. Recent studies supported that patients with constipation have altered intestinal microbial structures compared with healthy controls. Intestinal dysbiosis might be one possible pathophysiological mechanism causing constipation. Bacterial strains, such as Lactobacillus spp., have shown many beneficial effects on the amelioration of constipation. However, few studies reported the structural changes of intestinal microbiota post-intervention of probiotics. In this study, a bacterial mixture was administrated to rats with loperamide-induced constipation. Effects of the bacterial mixture on small intestine transit (SIT), faecal water content, and the intestinal microbiome in rats were evaluated. Meanwhile, we investigated several factors involved in signalling pathways that regulate function of ICC and expression of AQP3 to discuss the possible underlying molecular mechanisms. Intervention of the bacterial mixture improved SIT and faecal water content in constipated rats. The up-regulation of C-kit/SP signalling pathways in ICC and AQP3 significantly contributed to improvements. These changes were closely associated with the manipulation of intestinal dysbiosis in constipated rats. Furthermore, our results revealed the important role of intestinal microbiota in affecting gut motility through regulation of serotonin biosynthesis. This monoamine neurotransmitter, secreted from enterochromaffin cells, up-regulated both substance P/neurokinin 1 receptors pathway of ICC and the expression of AQP3 in intestinal epithelial cells. Our study suggested that the disrupted microbiome in patients could be a potential therapeutic target for the improvement of constipation.
This study examined the effects on intestinal microbiota and diarrhoea of Lactobacillus buchneri supplementation to the diet of weaning Rex rabbits. To this end, rabbits were treated with L. buchneri at two different doses (LC: 10(4) cfu/g diet and HC: 10(5) cfu/g diet) for 4 weeks. PCR-DGGE was used to determine the diversity of the intestinal microbiota, while real-time PCR permitted the detection of individual bacterial species. ELISA and real-time PCR allowed the identification of numerous cytokines in the intestinal tissues. Zonula occludens-1, polymeric immunoglobulin receptor and immunoglobulin A genes were examined to evaluate intestinal barriers. Results showed that the biodiversity of the intestinal microbiota of weaning Rex rabbits improved in the whole tract of the treated groups. The abundance of most detected bacterial species was highly increased in the duodenum, jejunum and ileum after L. buchneri administration. The species abundance in the HC group was more increased than in the LC group when compared to the control. Although the abundance of Enterobacteriaceae exhibited a different pattern, Escherichia coli was inhibited in all treatment groups. Toll-like receptor (TLR) 2 and TLR4 genes were down-regulated in all intestinal tissues as the microbiota changed. In the LC group, the secretion of the inflammatory cytokine tumour necrosis factor-a was reduced, the gene expression of the anti-inflammatory cytokine interleukin (IL)-4 was up-regulated and the expression of intestinal-barrier-related genes was enhanced. Conversely, IL-4 expression was increased and the expression of other tested genes did not change in the HC group. The beneficial effects of LC were greater than those of HC or the control in terms of improving the daily weight gain and survival rate of weaning Rex rabbits and reducing their diarrhoea rate. Therefore, 10(4) cfu/g L. buchneri treatment improved the microbiota of weaning Rex rabbits and prevented diarrhoea in these animals.
This study aimed to demonstrate whether exposure to bifidobacteria during early life influences immunity and alleviates the risk of immunoglobulin E (IgE)-mediated allergies in adulthood. BALB/c neonatal mice (n=54) were administered with a lyophilised cell preparation of Bifidobacterium bifidum TMC3115 (TMC3115) for 3 weeks. Following the intervention, the mice were immunised with intraperitoneal ovalbumin (OVA). The morphology and function of the intestinal epithelium were determined using histopathological examinations. Intestinal microbiota was detected using quantitative PCR and characterised using next-generation sequencing of 16S rRNA genes from faecal DNA. Caecal short-chain fatty acids (SCFAs) were measured using gas chromatography-mass spectrometry. Serum levels of tumour necrosis factor (TNF)-alpha, interleukin (IL)-6, IL-10, and immunoglobulin E (IgE) and the percentage of splenic CD4+ T cells were examined using enzyme-linked immunosorbent assay and flow cytometry, respectively. TMC3115 did not significantly affect body weight, and cause any severe systemic inflammation or other clinical symptoms among the neonatal or adult mice, although the crypt depths and Muc2-positive cells in some intestinal segments of neonatal mice were significantly lower than control. Oral TMC3115 administration significantly increased faecal microbial diversity, relative abundance of Bacteroidetes and caecal SCFAs production in neonatal mice. Following the intervention, neonatal mice treated with TMC3115 exhibited less increase in serum IgE levels induced by OVA in adults and significantly higher TNF-alpha and IL-10 levels than in control. Our findings indicate that the oral administration of bifidobacteria, particularly certain strains, such as TMC3115, during early life could alleviate the risk of IgE-mediated allergies in adult host animals. Modifications of intestinal microbiota, SCFAs metabolism and anti-inflammatory cytokine IL-10 production by bifidobacteria may at least in part be a key mechanism underlying the effect of bifidobacteria on the IgE-mediated immune sensitivity of hosts to attacks by allergens at both neonatal and adult stages.
Ulcerative colitis is a type of chronic inflammation present in the intestines for which the aetiology is not yet clear. The current therapies for ulcerative colitis cannot be considered to be long-term management strategies due to their significant side effects. Therefore, it is essential to identify an alternative therapeutic strategy for ulcerative colitis. The present study focused on the evaluation of the anti-inflammatory activities of Lactobacillus acidophilus CGMCC 7282 and Clostridium butyricum CGMCC 7281. The roles of both single and combination of L. acidophilus CGMCC 7282 and C. butyricum CGMCC 7281 in ulcerative colitis were investigated in 2,4,6-trinitrobenzenesulfonic acid-induced acute colitis (Th1-type colitis) in Sprague-Dawley rats and oxazolone-induced chronic colitis (Th2-type colitis) in BALB/c mice. The in vivo studies showed that the administration of L. acidophilus CGMCC 7282, C. butyricum CGMCC 7281 and L. acidophilus CGMCC 7282 plus C. butyricum CGMCC 7281 could reduce the Th1-type colitis as well as the Th2-type colitis, and the combination of the two strains exhibited the most notable effects, as indicated by the reduced mortality rates, the suppressed disease activity indices, the improved body weights, the reduced colon weight/colon length and colon weight/body weight ratios, and the improved gross anatomic characteristics and histological features (ameliorations of neutrophil infiltration and ulceration in the colon). It was found that the alterations of the gut microbiome, the barrier function changing and the selected inflammation-related cytokines are observed in the ulcerative colitis rats/mice treated with L. acidophilus CGMCC 7282 and C. butyricum CGMCC 7281. The combination of L. acidophilus CGMCC 7282 plus C. butyricum CGMCC 7281 also exerted a stronger anti-inflammatory effect than either of the single strains alone in vitro. These findings provide evidence that the administration of L. acidophilus CGMCC 7282 plus C. butyricum CGMCC 7281 may be a promising therapy for ulcerative colitis.
Bacillus is widely used in the livestock industry. This study was designed to evaluate the effects of probiotic Bacillus amyloliquefaciens SC06 (Ba), originally isolated from soil, in piglets diet as an alternative to antibiotics (aureomycin), mainly on intestinal epithelial barrier and immune function. Ninety piglets were divided into three groups: G1 (containing 150 mg/kg aureomycin in the diet); G2 (containing 75 mg/kg aureomycin and 1 x 10(8) cfu/kg Ba in the diet); G3 (containing 2x 10(8) cfu/kg Ba in the diet without any antibiotics). The results showed that, compared with the antibiotic group (G1), villus length, crypt depth and villus length/crypt depth ratio of intestine significantly increased in the G2 and G3 groups. In addition, intestinal villi morphology, goblet-cell number, mitochondria structure and tight junction proteins of intestinal epithelial cells in G2 and G3 were better than in G1. The relative gene expression of intestinal mucosal defensin-1, claudin3, claudin4, and human mucin-1 in G3 was significantly lower, while the expression of villin was significantly higher than in the antibiotic group. Probiotic Ba could significantly decrease serum interferon (IFN)-IFN-gamma, interleukin (IL)-1 beta, and IL-4 levels, whereas increase tumour necrosis factor (TNF)-alpha and IL-6 secretion. Ba could also significantly decrease cytokines TNF-alpha, IFN-gamma, IL-1 beta, and IL-4 level in liver, whereas it significantly increased IFN-alpha. Furthermore, replacing antibiotics with Ba also significantly down-regulated gene expression of TNF and IL-1 alpha in intestinal mucosa, but up-regulated IL-6 and IL-8 transcription. Dietary addition of Ba could significantly reduce the gene expression of nuclear factor kappa beta (NF kappa B)-p50 and Toll-like receptor (TLR)6, while there was no significant difference for that of myeloid differentiation primary response 88, TNF receptor-associated factor-6, nucleotide-binding oligomerisation domain containing protein 1, TLR2, TLR4, and TLR9. Taken together, our findings demonstrated that probiotic Ba could increase the intestinal epithelial cell barrier and immune function by improving intestinal mucosa structure, tight junctions and by activating the TLRs signalling pathway.
Translocation of bacteria across the intestinal barrier is important in the pathogenesis of systemic sepsis and multiple organ dysfunction syndromes. Inflammatory cytokines increase paracellular permeability that allows increased luminal bacteria to translocate across mucosal epithelium and further deteriorate the gut barrier. In order to reduce this risk, the prophylactic use of probiotics has been recently addressed. In this paper, we investigate the protective role toward tumour necrosis factor (TNF)-a induced non-pathogenic Escherichia coli translocation across Caco-2 monolayers of Lactobacillus strains. According to our experimental data, Lactobacillus plantarum L9 and Lactobacillus acidophilus LA have good capacities to adhere to Caco-2 cells. Addition of L. plantarum L9 and L. acidophilus LA to the enterocyte monolayer surface result in significant inhibition of E. coli adhesion and cell internalisation. However, L. plantarum L9 and L. acidophilus LA did not inhibit the growth of the non-pathogenic E. coli B5 after 24 h incubation. Exposure to TNF-a for 6 h caused a dramatic increase in E. coli B5 translocation across Caco-2 cells, which was uncoupled from increases in paracellular permeability. Pretreatment with L. plantarum L9 prevent TNF-a induced transcellular bacterial translocation and IL-8 production in Caco-2 cells. L. plantarum L9 also did not affect the integrity of the monolayers, as indicated by lactate dehydrogenase release, horseradish peroxidase permeability, and transepithelial electrical resistance. L. plantarum L9 showed the potential to protect enterocytes from an acute inflammatory response and therefore could be good potential prophylactic agents in counteracting bacterial translocation.
This study was performed to evaluate the effects of dietary chitosan supplementation on growth performance, lipid metabolism, gut microbial, antioxidant status and immune responses of juvenile loach (Misgurnus anguillicaudatus). Five experimental diets were formulated to contain graded levels of chitosan (0 (control), 0.5, 1, 2 and 5% CHI) for 50 days. Results of the present study showed that body weight gain was significantly higher in fish fed chitosan supplemented diets in dose dependent manner than control group. Increasing dietary chitosan levels reduced gut lipid content. Meanwhile the mRNA expression levels of intestine lipoprotein lipase and fatty acid binding protein 2 were significantly reduced with incremental dietary chitosan level. The percentages of total monounsaturated fatty acid decreased, while polyunsaturated fatty acid increased with dietary chitosan. The fish fed 0.5% CHI had higher mucus lysozyme activity (LZM) than those fed 0% CHI, but the LZM activity was significantly decreased with advancing chitosan supplement. The expression levels of superoxide dismutase, catalase and glutathione peroxidase revealed a similar trend, where the highest expressions were found in fish fed 5% CHI diet. In the term of intestine microbiota between 0 and 1% CHI groups, the proportion of bacteria in the phylum Bacteroidetes increased, whereas the proportion of bacteria in the phylum Firmicutes decreased as the fish supplemented chitosan. In conclusion, supplementation of chitosan improved growth performance, antioxidant status and immunological responses in loach.