Part 2: Treatments for Chronic Gastrointestinal Disease and Gut Dysbiosis.

Part 1 of this review discussed the connection between the human gut microbiota and health. Manipulation of the intestinal microbiota holds promise as a prospective therapy for gut dysbiosis, ameliorating symptoms of gastrointestinal and systemic diseases and restoring health. The concept of probiotics has existed for more than 100 y, and modern research methods have established sound scientific support for the perceived benefits of probiotic bacteria, which mainly include Lactobacillus and Bifidobacterium genera. On the basis of these evidence-based functional approaches, dietary interventions that supplement the normal diet with probiotics or prebiotics are now considered as potentially viable alternatives or adjuncts to the use of steroids, immunosuppressants, and/or surgical interventions. Studies investigating the impact on gastrointestinal disorders, such as diarrhea, inflammatory bowel disease (IBD), irritable bowel syndrome (IBS); and systemic metabolic diseases, such as type 2 diabetes and obesity, in response to the use of probiotics and prebiotics are reviewed. Further, fecal microbial transplantation (FMT) is discussed as an exciting development in the treatment of gut dysbiosis using microbes.

Part 1: The Human Gut Microbiome in Health and Disease.

The bacterial cells harbored within the human gastrointestinal tract (GIT) outnumber the host's cells by a factor of 10 and the genes encoded by the bacteria resident within the GIT outnumber their host's genes by more than 100 times. These human digestive-tract associated microbes are referred to as the gut microbiome. The human gut microbiome and its role in both health and disease has been the subject of extensive research, establishing its involvement in human metabolism, nutrition, physiology, and immune function. Imbalance of the normal gut microbiota have been linked with gastrointestinal conditions such as inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS), and wider systemic manifestations of disease such as obesity, type 2 diabetes, and atopy. In the first part of this review, we evaluate our evolving knowledge of the development, complexity, and functionality of the healthy gut microbiota, and the ways in which the microbial community is perturbed in dysbiotic disease states; the second part of this review covers the role of interventions that have been shown to modulate and stabilize the gut microbiota and also to restore it to its healthy composition from the dysbiotic states seen in IBS, IBD, obesity, type 2 diabetes, and atopy.

A randomised cross-over trial in healthy adults indicating improved absorption of omega-3 fatty acids by pre-emulsification.

BACKGROUND: The health benefits of increased intakes of omega-3 fatty acids are well established but palatability often presents a problem. The process of emulsification is used in the food industry to provide a wider spectrum of use, often with the result of increased consumption. Moreover, as emulsification is an important step in the digestion and absorption of fats, the pre-emulsification process may enhance digestion and absorption. In this study the levels of plasma fatty acid and triacylglycerol (TAG) following the ingestion of either an oil mixture or an emulsified oil mixture have been compared. METHODS: In this randomised cross-over study, 13 volunteers received the oil mixture and 11 received the oil emulsion as part of an otherwise fat free meal. Blood samples were collected at 0, 1.5, 3, 4.5, 6, 7.5 and 9 hours after ingestion of oil, separated and stored at -20 degrees C. Plasma triacylglycerols were assessed spectrophotometrically and fatty acids were determined by gas chromatography. Following a washout period of twenty days the procedure was repeated with the assignments reversed. RESULTS: The postprandial plasma TAG and the C18:3 (n-6), C18:3(n-3), C20:5(n-3) and C22:6 (n-3) polyunsaturated fatty acid (PUFA) levels for the emulsified oil group were increased significantly (P = 0.0182; P = 0.0493; P = 0.0137; P < 0.0001; P = 0.0355 respectively) compared with the non-emulsified oil group. The C16:0 and C18:0 saturated fatty acids, the C18:1 (n-9) monounsaturated fatty acid and the C18:2 PUFA were not significantly different for the oil and emulsified oil groups. CONCLUSION: Pre-emulsification of an oil mixture prior to ingestion increases the absorption of longer chain more highly unsaturated fatty acids (especially eicosapentaenoic acid and docosahexaenoic acid) but does not affect absorption of shorter chain less saturated fatty acids, suggesting that pre-emulsification of fish oils may be a useful means of boosting absorption of these beneficial fatty acids.

Effect of probiotics on preventing disruption of the intestinal microflora following antibiotic therapy: a double-blind, placebo-controlled pilot study.

In this pilot-scale, double-blind, placebo-controlled trial, 30 patients with Helicobacter pylori infection were randomised into three groups prior to their 7 days eradication therapy, to study the effects of probiotic supplement comprising Lactobacillus acidophilus and Bifidobacterium bifidum on the intestinal microflora in response to antibiotic therapy. Group I received the placebo product from day 1 to day 15, Group II received placebo from day 1 to day 7 and probiotics from day 8 to day 15 and Group III received probiotics from day 1 to day 15. Patients provided stool samples for analysis on days 1, 7, 12, 17 and 27. For patients in Groups I and II, significant increases in the facultative anaerobe component of the microflora occurred between days 1 and 7. In Group I, the numbers remained elevated to day 27 but in Group II, the numbers decreased significantly between days 7 and 27 back to the starting levels. In Group III, the facultative anaerobe population remained stable throughout. The total anaerobe numbers increased significantly at day 27 than at day 1 for Group I, were unchanged throughout for Group II and decreased significantly for the patients in Group III between days 1 and 7 before reverting to the starting levels by day 27. From these results, it can be seen that probiotic supplementation modulates the response of the intestinal microflora to the effects of antibiotic therapy.