A Molecular Approach to Understanding the Role of Diet in Cancer-Related Fatigue: Challenges and Future Opportunities.

Cancer-related fatigue (CRF) is considered one of the most frequent and distressing symptoms for cancer survivors. Despite its high prevalence, factors that predispose, precipitate, and perpetuate CRF are poorly understood. Emerging research focuses on cancer and treatment-related nutritional complications, changes in body composition, and nutritional deficiencies that can compound CRF. Nutritional metabolomics, the novel study of diet-related metabolites in cells, tissues, and biofluids, offers a promising tool to further address these research gaps. In this position paper, we examine CRF risk factors, summarize metabolomics studies of CRF, outline dietary recommendations for the prevention and management of CRF in cancer survivorship, and identify knowledge gaps and challenges in applying nutritional metabolomics to understand dietary contributions to CRF over the cancer survivorship trajectory.

Comparison of methodological approaches to human gut microbiota changes in response to metabolic and bariatric surgery: A systematic review.

Substantial differences in the response of gut microbial composition to metabolic and bariatric surgery have been reported. Therefore, the goal of the present review is to evaluate if methodological differences could be driving this lack of consistency. A search was conducted using PUBMED, Web of Science, Science Direct and COCHRANE using the following inclusion criteria: human studies written in English with a baseline sampling point, using gut microbiota as an outcome and either Roux-n-Y gastric bypass or sleeve gastrectomy. Sixteen articles were selected (total 221 participants). Roux-n-Y gastric bypass caused more alterations in gut microbial composition in comparison with sleeve gastrectomy. Substantial variability was found in study designs, data collection and analyses across studies. Increases in several families and genera from the phylum Proteobacteria and Bacteroidetes, the family Streptococcaceae, the species Akkermansia muciniphila and Streptococcus salivarius and a decrease in the phylum Firmicutes and the family Bifidobacteriaceae were reported. There is a need for standardization not only of microbial analysis but also of study designs when analysing the effect of bariatric surgery on the human gut microbiome. In addition, outcomes from different surgical procedures should not be combined as they produce distinctive effects on gut microbial composition.