I was worried that I might not be able to stick to an intermittent fasting schedule during my vacation in Mexico. It turns out, it was a breeze.Because I was sick.It started on the plane ride to Cozumel, a tingle in my throat and then the telltale sign that illness was imminent: three sneezes in a row. A clogged nose, a slight fever and a general feeling of malaise came over me after my third dive into the electric blue waters of the Caribbean.I'm participating in a preliminary study at Johns Hopkins Medicine on the effects of intermittent fasting on the microbiome and inflammation in people with multiple sclerosis. For the six-month study, I'm restricted to eating during an eight-hour period, usually from noon until 8 p.m. That meant that the first day of vacation, my first meal was pretzels on a plane, my second was ceviche and nachos in the late afternoon.It wasn't a great combination, but I had a feeling that as my nose continued to clog, I wouldn't be able to taste much, so I went for variety. As the week went on, I tried not to let my inability to taste hamper the experience, but it was hard. Tacos tasted like rubber, plantains like Elmer's glue. And though I squealed in delight when I saw a churros cart, the deep-fried, buttery, cinnamon-sugary treats tasted more like cardboard covered in sawdust.My vacation was headed toward gastronomic disaster, but at least the study data would not be compromised.At the end of the six months, researchers will be looking at the state of my microbiome, via a stool sample, to determine how it may have changed. Or to be precise, my microbiota, according to Jorge Cervantes, an assistant professor of microbiology at the Texas Tech University Health Sciences Center, El Paso who has studied the microbiome in relation to several diseases, including MS. I called him to get up to speed on my microbiota."The microbiota is all the microorganisms living in a specific niche," he says. That niche being my gut. "We talk about bacteria, mainly, but there are also viruses and fungi."The microbiome is the whole ecosystem — the bacteria, viruses, fungi, as well as the environmental conditions they inhabit.Our resident bacteria serve us in three basic ways, says Cervantes, who is not involved in the study I'm doing. They occupy space and help restrict the overgrowth of bad bacteria. And they can help our metabolism by facilitating the breakdown of certain molecules.Gut bacteria are of special interest to people with autoimmune diseases, including multiple sclerosis, irritable bowel syndrome and Crohn's disease, because they help in the training and development of our immune systems.That's so that your immune system can sample a molecule and and tell, "'Oh this is bacteria,' or 'Oh, this is a virus.' " Cervantes explains. If the molecule might cause harm, an immune response is triggered.Once an immune cell locates a potentially harmful molecule — say, from the bacteria Streptococcus, or whatever I caught on the plane to Mexico — it sends out a call to other immune cells so they can help control the invasion, Cervantes says. That process creates inflammation, which can involve pain, stinging, swelling or a host of other unpleasant symptoms that ordinarily mean your body is fighting the good fight to help you heal."Sometimes," Cervantes said, "the immune cells get confused." And here's where our microbes can affect autoimmune diseases such as MS, in which the body's immune system fires up at the wrong times: bacteria can be the trigger for this confusion. An immune cell can mistake good bacteria for bad bacteria, and that confusion can lead to an immune response when there's no real threat to a person's health.Scientists are not only studying microbiota and their relationship to autoimmune diseases, they're studying their roles in hypertension, cancer, even mental health disorders.Research in many of these areas is new and exciting and full of potential — and faces challenges, one being the difficulty of teasing out cause and effect. Does a change in the volume and/or variety of a microbiota lead to disease? Does the disease change the microbiota, leading to other health changes?"The thing is, no one knows what is first, the egg or the chicken," Cervantes says.To answer that question, scientists have been turning to mice. Not just any mice, these rodents are squeaky-clean, entirely germ-free. According to a review published in 2015 in Microbial Ecology in Health and Disease, germ-free mice are less likely to have inflammatory bowel disease, autoimmune arthritis, Type 1 diabetes and other autoimmune diseases. And when they do have them, the symptoms are less severe.This, the authors say, is consistent with the idea that the microbiota could be a trigger for these diseases. Good news, right? But they go on to say that attempts to identify exactly which organisms could be causing these diseases have failed.And even if we can agree that we want a "healthy" gut microbiome, what does that mean? "There is no ideal," Cervantes says. "The point is that the microbiome is not a fixed entity." It changes over time and is different from person to person.And so it seems we've added a third variable to the already complex interplay of genetics and the environment when considering health and disease.I'm pleased to report that my immune system, while it may be overactive, also does its job once in a while, fighting back the infection as I hunkered down in my hotel room in Mexico.While I recuperated, I read through comments on the first article I wrote about my experiences with this study. People shared their own attempts to tweak their diets as means to ease suffering from a host of diseases. I also read a lot of criticism about my diet:
