Vitamin C improves gut <i>Bifidobacteria</i> in humans
Creators: name: Hazan, Sabine
name: Dave, Sonya
name: Papoutsis, Andreas J
name: Deshpande, Nirupama
name: Howell, Mark C
name: Martin, Leisha MA
Publisher: name: Taylor & Francis
Year: 2025
Subjects: subject: Microbiology
subject: FOS: Biological sciences
subject: Chemical Sciences not elsewhere classified
subject: Ecology
subject: Immunology
subject: FOS: Clinical medicine
subject: Biological Sciences not elsewhere classified
subject: Science Policy

description: <b>Aims:</b> Numerous beneficial effects of vitamin C (ascorbic acid) supplementation have been reported in the literature. However, data on its effects toward the gut microbiome are limited. We assessed the effect of vitamin C supplementation on the abundance of beneficial bacterial species in the gut microbiome. <b>Materials and methods:</b> Stool samples were analyzed for relative abundance of gut microbiome bacteria using next-generation sequencing-based profiling and metagenomic shotgun analysis. <b>Results:</b> Supplementation with vitamin C increased the abundance of bacteria of the genus <i>Bifidobacterium</i> (p = 0.0001) and affected various species. <b>Conclusion:</b> The beneficial effects of vitamin C supplementation may be attributed to modulation of the gut microbiome and the consequent health benefits thereof. Vitamin C, also known as ascorbic acid, is used as a supplement for fighting infectious disorders. Many disorders, including COVID-19 and cancer, harmfully disrupt the levels of bacteria that naturally reside in the gut, which may contribute to symptoms. The aim of the study was to understand whether high-dose vitamin C could improve the types of bacteria in the human gut. To do this we characterized the gut bacteria before and after 23 individuals took vitamin C, as prescribed by their respective physicians. We observed that vitamin C increased levels of a gut bacterium called <i>Bifidobacterium</i> which has positive health benefits, including fighting infection. This study suggests the possibility that vitamin C could be successful for improving infection outcomes, possibly even COVID-19, partially because it improves the gut bacteria present. Patients receiving ascorbic acid supplementation had increased abundance of <i>Bifidobacterium</i> in their gut microbiome, which may help to explain some of the apparent health benefits and antiviral properties of vitamin C. Low vitamin C concentrations have been reported in cognitively impaired patients, such as those with Alzheimer’s disease and dementia, and in patients with advanced cancer and severe SARS-CoV-2 infection. We hypothesized that vitamin C administration could modulate the gut microbiome contributing to protection from severe outcomes associated with viral illness, including SARS-CoV-2 infection. Supplementation with vitamin C increased the relative abundance of bacteria of the genus <i>Bifidobacterium</i>. Families Lachnospiraceae and Bifidobacteriaceae also significantly increased, and various species changed. Our observational study shows that vitamin C has microbiome-modulating properties, presenting a new potential mechanism for its therapeutic value. Moreover, the data demonstrate that vitamin C has a potential for creating Refloralization™ (restoration of the human gut microbiome) after <i>Bifidobacterium</i> depletion.