Bourgonje Arno R, Otten Antonius T, Sadaghian Sadabad Mehdi, von Martels Julius Z H, Bulthuis Marian L C, Faber Klaas Nico, van Goor Harry, Dijkstra Gerard, Harmsen Hermie J M
Department of Gastroenterology and Hepatology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands.
Department of Gastroenterology and Hepatology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands.
Free Radic Biol Med. 2022 Sep;190:169-178. doi: 10.1016/j.freeradbiomed.2022.08.008. Epub 2022 Aug 13.
Riboflavin is a redox-active vitamin that plays a pivotal role in human energy metabolism. Riboflavin may have beneficial health effects by increasing extracellular antioxidant capacity, thereby alleviating oxidative stress. Reduced levels of free thiols in blood reflect systemic oxidative stress, since they are readily oxidized by reactive species. In this study, we aimed to study the potential of riboflavin supplementation to improve the systemic redox status in healthy volunteers.
This study was a post-hoc analysis of the RIBOGUT study, a randomized, double-blind, placebo-controlled human intervention trial that investigated the effect of riboflavin supplements on the gut microbiota composition of healthy individuals. Serum free thiols were quantified before and after intervention and adjusted to serum albumin levels. Changes in albumin-adjusted free thiols were analyzed, as well as potential associations with routine laboratory parameters and faecal bacterial quantification by fluorescence in-situ hybridization (FISH).
Participants were randomized to either placebo (n = 34), riboflavin 50 mg daily (n = 32), or riboflavin 100 mg daily (n = 33). At baseline, no significant differences in albumin-adjusted serum free thiols were observed. After intervention with either placebo or riboflavin, albumin-adjusted serum free thiols did not significantly change (P > 0.05), however, observed changes were inversely associated with changes in C-reactive protein (CRP) levels (r = -0.22, P < 0.05). At baseline, albumin-adjusted serum free thiols were positively associated with faecal relative abundances of Faecalibacterium prausnitzii (P < 0.01).
Riboflavin did not change the systemic redox status in healthy individuals as reflected by serum free thiols, but observed changes in albumin-adjusted free thiol levels were negatively associated with changes in CRP levels. Strikingly, albumin-adjusted free thiols were independently associated with relative abundances of faecal F. prausnitzii, which may suggest a potential host redox-microbiota interaction.
核黄素是一种具有氧化还原活性的维生素，在人体能量代谢中起关键作用。核黄素可能通过增加细胞外抗氧化能力，从而减轻氧化应激，对健康产生有益影响。血液中游离硫醇水平降低反映了全身氧化应激，因为它们容易被活性物质氧化。在本研究中，我们旨在研究补充核黄素改善健康志愿者全身氧化还原状态的潜力。
本研究是对RIBOGUT研究的事后分析，RIBOGUT研究是一项随机、双盲、安慰剂对照的人体干预试验，研究核黄素补充剂对健康个体肠道微生物群组成的影响。在干预前后对血清游离硫醇进行定量，并根据血清白蛋白水平进行调整。分析了白蛋白调整后游离硫醇的变化，以及与常规实验室参数和荧光原位杂交（FISH）粪便细菌定量的潜在关联。
参与者被随机分为安慰剂组（n = 34）、每日50毫克核黄素组（n = 32）或每日100毫克核黄素组（n = 33）。在基线时，未观察到白蛋白调整后血清游离硫醇有显著差异。用安慰剂或核黄素干预后，白蛋白调整后血清游离硫醇无显著变化（P > 0.05），然而，观察到的变化与C反应蛋白（CRP）水平的变化呈负相关（r = -0.22，P < 0.05）。在基线时，白蛋白调整后血清游离硫醇与粪便中普拉梭菌的相对丰度呈正相关（P < 0.01）。
核黄素并未改变以血清游离硫醇反映的健康个体的全身氧化还原状态，但观察到的白蛋白调整后游离硫醇水平变化与CRP水平变化呈负相关。值得注意的是，白蛋白调整后游离硫醇与粪便中普拉梭菌的相对丰度独立相关，这可能提示宿主氧化还原与微生物群之间存在潜在相互作用。
