Different species of microbes thrive on different kinds of food. If they can prompt us to eat more of the food they depend on, they can multiply.
Microbial manipulations might fill in some of the puzzling holes in our understandings about food cravings, Dr. Maley said. Scientists have tried to explain food cravings as the body’s way to build up a supply of nutrients after deprivation, or as addictions, much like those for drugs like tobacco and cocaine.
But both explanations fall short. Take chocolate: Many people crave it fiercely, but it isn’t an essential nutrient. And chocolate doesn’t drive people to increase their dose to get the same high. “You don’t need more chocolate at every sitting to enjoy it,” Dr. Maley said.
Perhaps, he suggests, the certain kinds of bacteria that thrive on chocolateare coaxing us to feed them.
John F. Cryan, a neuroscientist at University College Cork in Ireland who was not involved in the new study, suggested that microbes might also manipulate us in ways that benefited both them and us. “It’s probably not a simple parasitic scenario,” he said.
More research is needed and time will tell! But speaking for myself (and drawing on the experiences of others) I will say that sugar cravings are real but do pass with time and restraint. That could tie in to the idea that the intestinal bugs screaming for sugar eventually dwindle in number and influence. But I can't rule out evil sprits or demonic possession.