eration of the two-seater that will be on the road in a couple of years. At the top of the list, and the car, are transparent solar cells that utilize light-activated organic dyes to generate electricity to power the Forvision's multimedia and climate control systems, even in low light. They also act as light-emitting diodes and can illuminate both the cabin and exterior of the car. Along with the lightweight plastic wheels, body panels are made from carbon fiber reinforced epoxy resins that are 50 percent ligher than steel, and a lightweight seating foam, which is upholstered in a heated e-textile that reduces the need to use the less-efficient cabin heating system. Even when you do turn it on, infared-reflective "heat shielding" on the windows helps to keep the interior cool in bright sunshine, as does a special metallic-look paint embedded with glass flakes. The cabin itself is a futuristic take on the simple, economical design of the current Smart Fortwo Electric Drive, with oval shapes contrasting with the complex polygons that wanted to see how these different types of gut bacteria affect human health. "The unique feature of the intestines is that they are constantly bathed in what we eat. It seemed logical to us that some of the differences between one person's gut bacteria and another could be related to what they eat," Lewis said in a telephone interview. To understand that, the team had to sort through a lot of excrement. "We fondly refer to this as the poop study," Lewis said. For the first part of the study, the team recruited 98 healthy volunteers and collected stool samples from each. The volunteers also filled out a detailed questionnaire of their eating habits. Then the researchers used high-tech gene sequencing machines to determine the genetic code of the bacteria living in the volunteers' colons. They found that the gut bacteria were largely from two distinct groups or enterotypes, one called Bacteroides that preferred a typical Western diet rich in meat and fat, and another called Prevotella that preferred a high-carbohydrate diet. Next, the team wanted to see if they could alter the gut bacteria by changing people's diets. They recruited 10 healthy people who checked into a hospital for a 10-day controlled eating study. Half of the group ate a high-fat, low-fiber diet, and the other ate a low-fat, high-fiber diet. Within 24 hours, the team saw changes in the composition of the gut bacteria but the overall enterotype remained the same. Lewis said the findings suggest bacteria that live in the gut are sensitive to short term changes in diet, but it may take a long-term