1.
Disruption of the Gut Ecosystem by Antibiotics.
Yoon, MY, Yoon, SS
Yonsei medical journal. 2018;59(1):4-12
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The gut microbiome is a complex ecosystem of different micro-organisms, such as bacteria, viruses and fungi, living in the human intestines. It’s involved in numerous functions, such as extracting energy and nutrition from food, protecting against disease-causing microorganisms, and supporting the immune system of the host, and therefore affecting human health and disease. This paper is a review of studies on the effects of antibiotics on the gut microbiota. It outlines how different types of antibiotics can alter the intestinal environment and the composition of the microbes, resulting in various physiological changes that can trigger disease. Relevant mechanisms, such as inflammatory response and the use of intestinal nutrients by infectious bacteria are discussed. Finally, it discusses faecal microbiota transplantation (FMT) and probiotics as treatment approaches, aimed at restoring a disturbed intestinal environment.
Abstract
The intestinal microbiota is a complex ecosystem consisting of various microorganisms that expands human genetic repertoire and therefore affects human health and disease. The metabolic processes and signal transduction pathways of the host and intestinal microorganisms are intimately linked, and abnormal progression of each process leads to changes in the intestinal environment. Alterations in microbial communities lead to changes in functional structures based on the metabolites produced in the gut, and these environmental changes result in various bacterial infections and chronic enteric inflammatory diseases. Here, we illustrate how antibiotics are associated with an increased risk of antibiotic-associated diseases by driving intestinal environment changes that favor the proliferation and virulence of pathogens. Understanding the pathogenesis caused by antibiotics would be a crucial key to the treatment of antibiotic-associated diseases by mitigating changes in the intestinal environment and restoring it to its original state.
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Effect of Bacillus subtilis C-3102 on loose stools in healthy volunteers.
Hatanaka, M, Yamamoto, K, Suzuki, N, Iio, S, Takara, T, Morita, H, Takimoto, T, Nakamura, T
Beneficial microbes. 2018;9(3):357-365
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The cause of IBS has yet to be established, however the role of the gut microbiota in modulating symptoms is the subject of significant recent research. This randomised, double-blind, placebo controlled trial of 88 healthy subjects with chronic diarrhoea, aimed to assess the impact of ingestion of probiotic strain Bacillus subtilis C-3102 over an 8 week period on patient symptoms. Approximately 8.5 billion spores of Bacillus subtilis C-3102 were administered daily to the treatment group, once a day, immediately after breakfast. The results, after 8 weeks of ingestion, showed: an improved Bristol Stool Chart score; a reduction in stool frequency; significantly decreased abdominal sounds; and significantly altered relative abundance of Lachnospira, Actinomyces and SMB53. Intake of 4 weeks or more were required to achieve these results. Even though this was a small study, nutrition and lifestyle practitioners looking to support the digestive health of IBS patients may wish to consider adding this probiotic strain to their recommendations on the grounds of improved symptoms of diarrhoea.
Abstract
Ingestion of Bacillus subtilis C-3102 spores (C-3102) has relieved the symptoms of diarrhoea in piglets and changed the composition of gut microbiota in humans. Recently, it was suggested that the composition of the human gut microbiota affects stool consistency. In this study, a double-blind, randomised, placebo-controlled trial was conducted to assess the preventive effects of chronic diarrhoea in healthy volunteers with loose stools by ingestion of C-3102. The results showed that oral doses of C-3102 tablets significantly decreased the Bristol Stool Scale score and stool frequency, and also significantly improved abdominal sounds. With regard to gut microbiota, the relative abundance of Lachnospira, Actinomyces and SMB53 were significantly changed. This study shows that C-3102 could be effective for treating loose stools (Trial registration: UMIN000022583, http://tinyurl.com/ya4refqn ).
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Probiotics for prevention of radiation-induced diarrhea: A meta-analysis of randomized controlled trials.
Liu, MM, Li, ST, Shu, Y, Zhan, HQ
PloS one. 2017;12(6):e0178870
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Acute radiation-induced diarrhoea is a potentially fatal side effect of radiotherapy for abdominal or pelvic cancers. The mechanisms are not yet known, but effects of the radiation on the microbiota may be a factor and probiotic treatment may therefore be beneficial. The authors of this meta-analysis looked at randomised controlled trials of probiotics in the prevention of radiation-induced diarrhoea with probiotics (there were not enough trials to evaluate probiotics for the treatment of radiation-induced diarrhoea). Only six studies qualified for inclusion into this meta-analysis, with a total of 917 patients (490 receiving probiotics, 427 controls). Compared with placebo, patients receiving probiotics had a significantly lower risk of developing diarrhoea, but there was no significant reduction in anti-diarrhoea medication use or Bristol scale stool form. Most studies did not report adverse events from probiotic treatment. The meta-analysis was limited by several factors: variety of bacterial strains, dosages and timings used, differences in cancer treatment (dose of radiotherapy, radiotherapy alone or with chemotherapy), variability of patient populations and diseases, and diagnostic criteria for diarrhoea.
Abstract
BACKGROUND Radiotherapy is commonly used for abdominal or pelvic cancer, and patients receiving radiotherapy have a high risk developing to an acute radiation-induced diarrhea. Several previous studies have discussed the effect of probiotics on prevention of radiation-induced diarrhea, but the results are still inconsistent. OBJECTIVE We performed a meta-analysis of randomized controlled trials (RCTs) to evaluate the efficacy of probiotic supplementation for prevention the radiation-induced diarrhea. METHODS Relevant RCTs studies assessing the effect of probiotic supplementation on clinical outcomes compared with placebo were searched in PubMed, EMBASE, and the Cochrane Library databases (up to March 30 2016). Heterogeneity was assessed with I2 and H2, and publication bias was evaluated using sensitive analysis. RESULTS Six trials, a total of 917 participants (490 participants received prophylactic probiotics and 427 participants received placebo), were included in this meta-analysis. Compared with placebo, probiotics were associated with a lower incidence of radiation-induced diarrhea (RR: 0.55; 95% CI: 0.34-0.88; P = 0.01; I2: 87%; 95% CI: 75%-94%; H2: 2.8; 95% CI: 2.0-4.0). However, there is no significant difference in the anti-diarrheal medication use (RR: 0.68; 95% CI: 0.40-1.14; P = 0.14) or bristol scale on stool form (RR: 0.64; 95% CI: 0.35-1.17; P = 0.14). CONCLUSION Probiotics may be beneficial to prevent radiation-induced diarrhea in patients who suffered from abdominal or pelvic cancers during radiotherapy period.