Dietary Patterns and Associated Microbiome Changes that Promote Oncogenesis

Abstract

The recent increases in cancer incidences have been linked to lifestyle changes that result in obesity and metabolic syndrome. It is now evident that these trends are associated with the profound changes that occur in the intestinal microbiome, producing altered microbial population signatures that interact, directly or indirectly, with potentially pro-carcinogenic molecular pathways of transcription, proliferation, and inflammation. The effects of the entire gut microbial population on overall health are complex, but individual bacteria are known to play important and definable roles. Recent detailed examinations of a large number of subjects show a tight correlation between habitual diets, fecal microbiome signatures, and markers of metabolic health. Diets that score higher in healthfulness or diversity such as plant-based diets, have altered ratios of specific bacteria, including an increase in short-chain fatty acid producers, which in turn have been linked to improved metabolic markers and lowered cancer risk. Contrarily, numerous studies have implicated less healthy, lower-scoring diets such as the Western diet with reduced intestinal epithelial defenses and promotion of specific bacteria that affect carcinogenic pathways. In this review, we will describe how different dietary patterns affect microbial populations in the gut and illustrate the subsequent impact of bacterial products and metabolites on molecular pathways of cancer development, both locally in the gut and systemically in distant organs.

Role of microbiota and microbiota‐derived short‐chain fatty acids in PDAC

“…Diet is the major component to the variation in gut microbiota, which in turn affect disease susceptibility, 116 directly affecting functional changes that accompany particular syndromes or diseases. [116][117][118] Diet-driven changes in microbial diversity cause variations in SCFAs and future studies are necessary to understand the long term effects of these variations.…”

“…Diet is the major component to the variation in gut microbiota, which in turn affect disease susceptibility, 116 directly affecting functional changes that accompany particular syndromes or diseases. [116][117][118] Diet-driven changes in microbial diversity cause variations in SCFAs and future studies are necessary to understand the long term effects of these variations. In a recent study mice fed with low fiber intake resulted in depletion of butyrate production, directly disrupting gut microbial diversity, causing systemic inflammation and death due to necrotizing pancreatitis.…”

“…120 The SCFAs are key for adjusting immune tolerance, improving gut barrier junctions and intestinal purge. 116 Appropriate SCFA concentrations are necessary to ensure healthy metabolism and prevent disease. 11,121 Moreover, F I G U R E 1 A graphical depiction of the associations between microbiome, SCFA and diet intake, and their effect on signaling pathways.…”

Antibiotic therapy is associated with an increased incidence of cancer

“…Furthermore, the intratumoral microbiota has a distinct signature in each tumor type (González-Sánchez and DeNicola 2021 ). It has been hypothesized that antibiotics may play a role in oncogenesis as a result of their effects on the gut microbiome (Ibragimova et al 2021 ). Although antibiotics are one of the most commonly prescribed types of medication worldwide (Bitterman et al 2016 ; Farooqui et al 2019 ), the association between specific antibiotics and various cancer entities has not been clearly delineated.…”

Assessing the influence of the Mediterranean diet on dental calculus microbiome composition: a pilot study

“…Diet is known to be one of the main factors associated with microbiome compositional shifts, explaining 60% of such variations 5 . Furthermore, adherence to a specific diet seems to promote the opportunistic pathogenesis of some microorganisms 6 . In this context, the oral tract microbiome is gaining attention as a new target of omics studies, as it can capture humans’ dietary habits, immune responses, and environmental factors 7 .…”