The development of your baby’s brain could be influenced by the microbes in their belly, scientists have found.

The trillions of microbes that live inside our guts play essential roles in a range of bodily processes, from digestion to mental health. The gut contains more than 100 million nerve cells—the highest concentration in any part of the body other than the brain. Now, we are also beginning to learn about the roles of these microbes in the earliest stages of our lives.

“The microbiome plays an important role in the early development of several systems, such as the nervous and immune system, as well as providing another layer of protection against pathogens [disease],” Sebastian Hunter, a researcher from the University of British Columbia who led a study on the subject published Wednesday in the scientific journal PLOS One, told Newsweek.

You could be walking around with an unruptured brain aneurysm. But don’t panic – the Brain Aneurysm Foundation estimates that about 1 in 50 people in the U.S. has an unruptured brain aneurysm. Director of Endovascular Neurosurgery Koji Ebersole, MD, says people are surprised to learn that the majority of aneurysms don’t cause any symptoms.

An aneurysm develops when a vessel in the brain has a thin spot, which then fills with blood, creating a bulge or balloon shape. Most brain aneurysms are small, about the size of a pea. Because the brain itself has no sensory fibers, there is no pain and the brain doesn’t register that the aneurysm is there.

“Most patients find out they have an aneurysm for a completely unrelated reason,” Dr. Ebersole says. “Maybe they’re having trouble with their sinuses and have a CT scan and the doctors find an aneurysm. When you learn you have an aneurysm, it’s important to meet with a physician who’s practiced in neurology to talk about the implications.”

A recent study published in BMJ Gut conducted using a nationwide medical record network in the United States has shed light on potential links between gastrointestinal (GI) syndromes and the development of Parkinson’s disease (PD). Researchers led by Bo Konings aimed to determine whether specific GI conditions and interventions precede the onset of PD when compared with negative controls, Alzheimer’s disease (AD), and cerebrovascular diseases (CVD).

Here are the key findings from the study:

● PD-Specific Associations: The study identified several GI conditions that exhibited specific associations with PD in both case-control and cohort analyses. These conditions included gastroparesis, dysphagia, irritable bowel syndrome (IBS) without diarrhoea, and constipation.