Author: Elissa Mortimer
Mortimer, Elissa, 2023 An investigation into the feasibility and effect of dietary resistant starch supplementation in HIV-positive adults in India., Flinders University, College of Medicine and Public Health
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Globally, human immunodeficiency virus (HIV) continues to cause disease and loss of life, with 1.5 million people becoming infected in 2021 and 650 000 deaths attributed to AIDS-related illness. In developing countries, HIV disease is likely worsened by a gut malabsorption syndrome caused by unsafe water and inadequate sanitation, compromising health, education, economic and societal outcomes.
The gut microbiota refers to bacteria which live throughout the gastrointestinal (GI) system. HIV disease and antiretroviral therapy (ART) both result in gut microbiota changes. This dysbiosis results in aberrant gastrointestinal function. Correcting these effects will improve morbidity and likely improve adherence to ART, potentially reducing population viral load and decreasing transmission. Dietary supplementation with resistant starch (RS) derived from maize is a low-cost intervention that provides clinical benefit in several gut inflammatory conditions by increasing the production of short-chain fatty acids (SCFAs), improving gut integrity, and reducing bacterial translocation.
The objective of the work described here was to determine the feasibility and effect of RS supplementation in people living with HIV in India, a low-to-middle-income country (LMIC) where malnutrition arising from environmental enteric dysfunction (EED) exacerbates morbidity from HIV and other co-morbid conditions. In addition to an exploratory study of feasibility, it was hypothesised that RS would be fermented in the large intestine by gut microbiota, resulting in increased intestinal SCFAs, and that an associated decrease in pH would be observed. These changes to the colonic luminal environment were postulated to favour gut microbiota with beneficial functions, providing a selective advantage to these bacteria and correcting dysbiosis. This thesis represents an original contribution to knowledge, being the first study using a sole RS supplement in an HIV-positive population.
The feasibility assessment demonstrated that RS is a safe, well-tolerated and acceptable intervention in this population, providing a basis for intervention studies with HIV-positive populations in other settings. While this study did not produce evidence of any effect of RS supplementation on primary or secondary outcome measures, a trend was observed in CD4+ T cell response to RS supplementation that warrants further investigation. These results will inform the design of future studies.
Keywords: nutrition, resistant starch, dietary supplementation, HIV, microbiota, microbiome, low-to-middle-income country, environmental enteric dysfunction, antiretroviral therapy, feasibility, treatment effect, global health, India
Subject: Nutrition thesis
Thesis type: Professional Doctorate
Completed: 2023
School: College of Medicine and Public Health
Supervisor: Professor Geraint Rogers