How gut microbiota affects your mood
Medical conditions associated with changes in mood, such as irritable bowel syndrome (IBS) and chronic fatigue syndrome (CFS), might also be related to gut microbiota.
IBS is considered a “gut-brain disorder”, since it is often worsened by stress. Half of IBS sufferers also have difficulties with depression or anxiety.
Ongoing research is investigating whether gut bacteria are one reason for the mood symptoms in IBS, as well as the gastrointestinal pain, diarrhoea and constipation.
Similarly, CFS is a multi-system illness, with many patients experiencing unbalanced gut microbiota. In these patients, alterations in the gut microbiota may contribute to the development of symptoms such as depression, neurocognitive impairments (affecting memory, thought and communication), pain and sleep disturbance.
The exact contributions of stress and other factors such as intestinal permeability (which allows nutrients to pass through the gut) to these disorders are not understood. But the downstream effects seem to be involved in IBS, inflammatory bowel conditions, CFS, depression and chronic pain.
How our gut affects our sleep
Our mental health is closely linked to the quality and timing of our sleep. Now evidence suggests that the gut microbiota can influence sleep quality and sleep-wake cycles (our circadian rhythm).
A study this year examined patients with CFS. The researchers found that higher levels of the “bad” clostridium bacteria were associated with an increased likelihood of sleep problems and fatigue, but this was specific to females only. This suggests that an unbalanced gut may precipitate or perpetuate sleep problems.