Obesity-associated cancer risk: the role of intestinal microbiota in the etiology of the host proinflammatory state

Abstract

Obesity increases the risks of many cancers. One important mechanism behind this association is the obesity-associated pro-inflammatory state. Although the composition of the intestinal microbiome undoubtedly can contribute to the pro-inflammatory state, perhaps the most important aspect of host-microbiome interactions is host exposure to components of intestinal bacteria that stimulate the inflammatory reactions. Systemic exposures to intestinal bacteria can be modulated by dietary factors by altering both the composition of the intestinal microbiota as well as absorption of bacterial products from the intestinal lumen. In particular, high fat and high energy diets have been shown to facilitate absorption of bacterial lipopolysaccharide (LPS) from intestinal bacteria. Biomarkers of bacterial exposures that have been measured in blood include LPS-binding protein, sCD14, fatty acids characteristic of intestinal bacteria and immunoglobulins specific for bacterial LPS and flagellin. The optimal strategies to reduce these pro-inflammatory exposures, whether by altering diet composition, avoiding a positive energy balance or reducing adipose stores, likely differ in each individual. Biomarkers that assess systemic bacterial exposures therefore should be useful to optimize and personalize preventive approaches for individuals and groups with specific characteristics, and to gain insight into the possible mechanisms involved with different preventive approaches.

Introduction and Basic Concepts of Cancer

“…Recently, gall bladder, liver, thyroid, and ovarian cancers have been identified to be strongly affected by obesity (Djuric, 2016). Obesity-related mechanisms are found to be involved in various neoplastic processes such as cell proliferation, carcinogenesis, and angiogenesis.…”

“…Obesity-related mechanisms are found to be involved in various neoplastic processes such as cell proliferation, carcinogenesis, and angiogenesis. Moreover, obesity is associated with comorbidities and poor prognosis in cancer patients (Sánchez-Lara et al, 2010;Whiteman and Wilson, 2016;Djuric, 2016). Few other findings revealed body fatness as measured by body mass index (BMI) to be a plausible causative factor of ovarian cancer and advanced prostate cancer, and it was well evinced to have a strong association with liver cancer.…”

“…However, obesity-associated cancer risk is influenced by diverse factors like ethnicity, sex, menopausal status, etc. (Djuric, 2016).…”

Nutritional aspects and vitamin D supplementation in ankylosing spondylitis

“…The large amount of microbes on the intestinal microbiota can be associated with high levels of immunoglobulin A (IgA), and increased inflammation in patients with AS 28 . Djuric et al, also pointed that high fat and high carbohydrates diets could facilitate the absorption of bacterial lipopolysaccharide (LPS) by the bacterial of the intestine and thus stimulate inflammatory reactions in the intestine 29 . All of the aforementioned indicated the key role of prebiotics and complex carbohydrates in growth, reproduction and the time life of many enterobacteriaceae factors in the colon.…”

A Possible Role of Intestinal Microbiota in the Pathogenesis of Ankylosing Spondylitis

“…For example, it has been shown that a high intake of carbohydrates, particularly oligosaccharides, can stimulate the growth of Bifidobacterium spp., Klebsiella spp., Clostridium spp., and Escherichia coli in the human colon [128]. Furthermore, high-energy diets have been shown to facilitate absorption of bacterial lipopolysaccharide (LPS) from intestinal bacteria [129]. Several reports have indicated that a low-starch diet has potential mechanisms of benefit for AS.…”