The effect of probiotics on CD4 counts among people living with HIV: a systematic review

Probiotics are defined by the WHO as 'live microorganisms which when administered in adequate amounts confer a health benefit on the host'. Ongoing research has shown probiotics provide benefits to humans, including protection and restoration of the gastrointestinal and other mucosal tracts. As human immunodeficiency virus (HIV) activates gut-associated lymphoid tissue (GALT), several studies have investigated the effect of probiotics on CD4 cell count and related outcomes among those living with HIV. These studies are summarised here. Manuscripts were identified using the search terms 'probiotics', 'synbiotics', 'HIV', and 'CD4', and were reviewed for relevance and inclusion of CD4 count as an immunologic endpoint. Bibliographies of relevant manuscripts were also reviewed for additional studies matching inclusion and exclusion criteria. The search yielded 91 results; 13 included relevant outcomes. Seven of these studies produced beneficial CD4 outcomes, while the remaining 6 reported on insignificant beneficial or negative CD4 outcomes. The studies summarised here collectively suggest that daily consumption of probiotics over a prolonged period of time may improve CD4 count in people living with HIV.