Many people think staying up late only leads to feeling foggy or gaining weight the next day—but your gut microbes may be affected too. Sleep deprivation has become a global health concern, not only affecting memory but also disrupting gastrointestinal function. Previous studies have shown that melatonin helps regulate the biological clock and can improve memory deficits and gut dysbiosis caused by sleep deprivation, although the underlying mechanisms remain unclear.

A 2023 study published in Microbiome revealed that insufficient sleep not only worsens memory but also disrupts the gut microbiota and causes inflammation in the brain—and melatonin appears to act as a key protective factor.

Image provided by the Department and Institute of Physiology, College of Medicine, National Yang Ming Chiao Tung University

Scientists subjected mice to long-term sleep deprivation. The sleep-deprived mice showed an increase in the harmful gut bacterium Aeromonas and LPS, along with a reduction in the beneficial bacterium Lachnospiraceae_NK4A136 and its metabolite butyrate. These microbial changes were accompanied by overactivation of microglia and neuronal apoptosis in the hippocampus, memory deficits, and gut dysbiosis. Remarkably, when gut microbes from these “sleep-deprived mice” were transplanted into healthy mice, the recipients quickly became forgetful and anxious.

When melatonin was introduced, the situation completely reversed—transplanting gut microbes from sleep-deprived + melatonin–treated mice led to reduced brain inflammation and restored memory in recipient mice. The study found that the key lies in the beneficial metabolite butyrate, which protects neurons by regulating inflammation via crosstalk between the TLR4/NF-κB and MCT1/HDAC3 pathways. Conversely, direct colonization with Aeromonas or supplementation with LPS induced hippocampal inflammation and impaired spatial memory.

In short, keeping your biological clock aligned is crucial for maintaining a healthy brain–gut connection. This research shows that melatonin, together with gut microbes and their metabolite butyrate, can help protect the brain from the harmful effects of sleep deprivation. Maintaining regular sleep patterns to support natural melatonin production and consuming fiber-rich or fermented foods that promote butyrate formation may help reduce inflammation and support brain health.

This article is contributed by Prof. Li-Ling Wu and her research team at the Department and Institute of Physiology and the Microbiota Research Center, College of Medicine, National Yang Ming Chiao Tung University.

Source: Liberty Times