Photo Credit: Derek Yu

Another reason to avoid meat and dairy products produced with antibiotics:  beneficial gut bacteria are critical for healthy immune systems. In fact, a new research study published in Cell Host & Microbe suggests that a strong ecosystem of beneficial gut bacteria can help promote resistance to some diseases. The Caltech research team examined the difference between mice born with and without gut bacteria, and found that the mice that did not have gut bacteria also had fewer immune cells than healthy mice with a normal population of microbes in their gut. The gut bacteria-free mice were also more susceptible to Listeria infection. "It's interesting to see that these microbes are having an immune effect beyond where they live in the gut," said Arya Khosravi, the study’s lead author. "They're affecting places like your blood, spleen, and bone marrow -- places where there shouldn't be any bacteria."  This study shows the importance of maintaining a healthy gut bacterial population.