Fructooligosaccharides on inflammation, immunomodulation, oxidative stress, and gut immune response: a systematic review

CONTEXT

Evidence shows that fructooligosaccharides (FOSs) can modulate inflammatory, oxidative, and immune activity in the gut, possibly leading to a systemic response, improving human health.

OBJECTIVE

To assess the present knowledge of the effects of FOSs on inflammation, immunomodulation, oxidative stress, and gut immune response.

DATA SOURCES

Studies published between December 2000 and January 2020 were systematically searched in four databases: MEDLINE, LILACS, Web of Science, and Scopus. After the screening of 1316 articles, 8 human studies and 20 animal models were included.

DATA EXTRACTION

Data were extracted separately by 2 reviewers. For each study, the design, population, exposures, main results, and conclusion were extracted. The research questions and the risk-of-bias information were also extracted. Additionally, the risk-of-bias were analyzed to guarantee the reliability of this review.

DATA ANALYSIS

A qualitative analysis revealed that FOSs can increase bifidobacteria counts and short-chain fatty acids in the gut, stimulate IgA secretion in the colon, and decrease proinflammatory cytokines, thus influencing metabolic diseases.

CONCLUSION

Studies suggest that FOS supplementation is positively associated with an anti-inflammatory and antioxidant effect, thus enhancing the gut immune system, which may be beneficial for the host's health.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration nos 42020209865 and 42020220369.

Systematic review of the ingestion of fructooligosaccharides on the absorption of minerals and trace elements versus control groups

BACKGROUND & AIMS

Fructooligosaccharides (FOS) are non-caloric and unconventional sugars that are not metabolized by the human body, but can be fermented by the colonic microbiota, leading to some beneficial effects on the absorption of minerals and trace elements. There is, however, a lack of research that describes the continued consumption of FOS in the diet between healthy and ill individuals and their impact. The objective of this systematic review was to evaluate the evidence behind the role of FOS in the absorption of minerals and trace elements in the human body.

METHODS

The bibliographic research covered the period from January 2000 to August 2020. Four databases were investigated. We follow the Preferred Reporting Items for Systematic Reviews and Meta-Analyzes (PRISMA). The systematic review protocol was recorded in PROSPERO (139621). Two reviewers examined and extracted data from qualitative and quantitative studies published in the main databases, through a careful analysis. The risk of bias was assessed by four reviewers.

RESULTS

Of a total of 1494 texts, 30 complete articles composed this review. Two overarching categories represented the results: animal models and human models (randomized crossover design). Regarding human models, the results showed an improvement in minerals, especially the absorption of calcium, magnesium and iron after the ingestion of FOS, and specifically the absorption of minerals and trace elements in postmenopausal women was improved.

CONCLUSIONS

The use of FOS to improve the absorption of minerals and trace elements seems to be beneficial with evidence corroborating both in human and animal studies. However, the literature lacks articles exploring the daily dose and duration for FOS benefits, as well as long-term side effects in healthy or unhealthy subjects. Future research should focus on addressing the extent of the functional effect of this fiber and identifying the impact on overall health.