In 2019, the International Scientific Association for Probiotics and Prebiotics (ISAPP) convened a panel of experts specializing in nutrition, microbial physiology, gastroenterology, paediatrics, food science and microbiology to review the definition and scope of postbiotics. The term ‘postbiotics’ is increasingly found in the scientific literature and on commercial products, yet is inconsistently used and lacks a clear definition. The purpose of this panel was to consider the scientific, commercial and regulatory parameters encompassing this emerging term, propose a useful definition and thereby establish a foundation for future developments. The panel defined a postbiotic as a “preparation of inanimate microorganisms and/or their components that confers a health benefit on the host”. Effective postbiotics must contain inactivated microbial cells or cell components, with or without metabolites, that contribute to observed health benefits. The panel also discussed existing evidence of health-promoting effects of postbiotics, potential mechanisms of action, levels of evidence required to meet the stated definition, safety and implications for stakeholders. The panel determined that a definition of postbiotics is useful so that scientists, clinical triallists, industry, regulators and consumers have common ground for future activity in this area. A generally accepted definition will hopefully lead to regulatory clarity and promote innovation and the development of new postbiotic products.

Background & Aims Although functional gastrointestinal disorders (FGIDs), now called disorders of gut-brain interaction, have major economic effects on health care systems and adversely affect quality of life, little is known about their global prevalence and distribution. We investigated the prevalence of and factors associated with 22 FGIDs, in 33 countries on 6 continents. Methods Data were collected via the Internet in 24 countries, personal interviews in 7 countries, and both in 2 countries, using the Rome IV diagnostic questionnaire, Rome III irritable bowel syndrome questions, and 80 items to identify variables associated with FGIDs. Data collection methods differed for Internet and household groups, so data analyses were conducted and reported separately. Results Among the 73,076 adult respondents (49.5% women), diagnostic criteria were met for at least 1 FGID by 40.3% persons who completed the Internet surveys (95% confidence interval [CI], 39.9–40.7) and 20.7% of persons who completed the household surveys (95% CI, 20.2–21.3). FGIDs were more prevalent among women than men, based on responses to the Internet survey (odds ratio, 1.7; 95% CI, 1.6–1.7) and household survey (odds ratio, 1.3; 95% CI, 1.3–1.4). FGIDs were associated with lower quality of life and more frequent doctor visits. Proportions of subjects with irritable bowel syndrome were lower when the Rome IV criteria were used, compared with the Rome III criteria, in the Internet survey (4.1% vs 10.1%) and household survey (1.5% vs 3.5%). Conclusions In a large-scale multinational study, we found that more than 40% of persons worldwide have FGIDs, which affect quality of life and health care use. Although the absolute prevalence was higher among Internet respondents, similar trends and relative distributions were found in people who completed Internet vs personal interviews.

Summary: Background: Irritable bowel syndrome (IBS) is a chronic functional bowel disorder. Disturbances in the gastrointestinal microbiome may be involved in its aetiology.Aim: To perform a systematic review and meta‐analysis to examine the efficacy of prebiotics, probiotics, synbiotics and antibiotics in IBS.Methods: MEDLINE, EMBASE, and the Cochrane Controlled Trials Register were searched (up to July 2017). Randomised controlled trials (RCTs) recruiting adults with IBS, comparing prebiotics, probiotics, synbiotics or antibiotics with placebo or no therapy were eligible. Dichotomous symptom data were pooled to obtain a relative risk (RR) of remaining symptomatic after therapy, with a 95% confidence interval (CI). Continuous data were pooled using a standardised mean difference with a 95% CI.Results: The search identified 4017 citations. Data for prebiotics and synbiotics were sparse. Fifty‐three RCTs of probiotics, involving 5545 patients, were eligible. Particular combinations of probiotics, or specific species and strains, appeared to have beneficial effects on global IBS symptoms and abdominal pain, but it was not possible to draw definitive conclusions about their efficacy. There were five trials of similar design that used rifaximin in non‐constipated IBS patients, which was more effective than placebo (RR of symptoms persisting = 0.84; 95% CI 0.79‐0.90). Adverse events were no more common with probiotics or antibiotics.Conclusions: Which particular combination, species or strains of probiotics are effective for IBS remains, for the most part, unclear. Rifaximin has modest efficacy in improving symptoms in non‐constipated IBS.