Interplay of obesity and parasitic infection: current evidence of immunogenesis, tumorigenesis and leptin receptor involvement.

BACKGROUND

Parasitic infections possess comparable risk factors to obesity. In addition, obesity impairs innate and adaptive immunity subsequently increasing vulnerability to infectious diseases.

AIM

The study investigated the leptin/leptin receptors, obesity-parasites mutual relationship and the effect of parasitic infections on immune metabolism, microbiota, and tumorigenesis in the context of obesity.

METHODOLOGY

To implement the current review, articles were gathered using the Egyptian Knowledge Bank (EKB), Web of Science, PubMed, and Google Scholar.

CONCLUSION

Leptin enhances anti-parasitic immunity. Obesity favors intestinal colonization of Blastocystis sp., Dientamoeba fragilis, Entamoeba coli, and Giardia intestinalis. Adipocytes act as a niche and a food source for Trypanosoma cruzi, Trypanosoma brucei, and Plasmodium. In addition, Toxoplasma gondii relies on the circulatory cholesterol to thrive. Obesity provokes low-grade chronic inflammation and metabolic syndrome. Yet, Nippostrongylus brasiliensis and Fasciola hepatica attempted to alleviate inflammation and metabolic syndrome. Hookworm improves insulin resistance. However, parasites such as Schistosoma mansoni, Trichuris suis, Taenia pisiformis, Entamoeba histolytica, Trypanosoma cruzi, and Trypanosoma brucei, and Toxoplasma aggravated metabolic immune metabolic syndrome. Obesity hampered immunity against Leishmania sp.. and Plasmodium sp. is diabetogenic. Giardia infection and Heligmosoides polygyrus infections induce dysbiosis in obesity. Obesity and parasites like Trichomonas vaginalis, S. haematobium, S. mansoni, Clonorchis sinensis, Opishorchis viverrini showed similar cancer types. Yet, Toxoplasma gondii and Echinococcus granulosus have anti-tumorigenic effects. Obesity/high-fat diet hinders Schistosoma mansoni, Trichuris muris, and Entamoeba histolytica infections. Also, Blastocystis sp., Dientamoeba fragilis, Giardia intestinalis, Trichinella spiralis, and Schistosoma appeared to have ameliorative effects in obesity.