Could a popular food ingredient raise the risk for diabetes and obesity? New report outlines tips for making your house a healthy one The dietary factor Just 7,500 steps a day lowers mortality in older women, study says This discovery launches an array of new questions, said Carmody. One area of inquiry will be exploring how gut microbes handle the antimicrobial properties of some raw vegetables, and how these foodborne antimicrobial compounds affect our health more broadly. Another will look at whether cooking has represented a selective pressure favoring co-evolution between humans and our resident microbes.“It’s pretty clear that the human body has been shaped by our long history of cooking, but this study suggests the human gut microbiome would have been affected, too,” Carmody said.Other authors of the paper included Kylynda Bauer, Katia Chadaideh, and Vayu Maini Rekdal of Harvard University; Corinne F. Maurice of Harvard and McGill universities; and Jordan Bisanz, Elizabeth Bess, Peter Spanogiannopoulos, and Qi Yan Ang of UCSF.“It was exciting to see that the impact of cooking we see in rodents is also relevant to humans,” said Turnbaugh in a statement from UCSF. “We’re very interested in doing larger and longer intervention and observational studies in humans to understand the impact of longer-term dietary changes.”For Carmody, it has had an even more profound effect. “As a human evolutionary biologist, I’ve reached the point where I’m not totally sure what a human is — where our biology ends and the environment begins. At the end of the day, we are holobionts — ecosystems unto ourselves — and we’ll have to understand these ecosystem interactions in order to better understand ourselves.” How we prepare food matters to us, surprisingly deeply, it turns out.Scientists have recently discovered that different diets — say, high-fat versus low-fat, or plant-based versus animal-based — can rapidly and reproducibly alter the composition and activity of the gut microbiome, where differences in the composition and activity can affect everything from metabolism to immunity to behavior.“What we didn’t know was whether the form of the food also mattered,” said Rachel Carmody, assistant professor in the Department of Human Evolutionary Biology. And the answer is apparently yes. Carmody co-led teams at Harvard and the University of California, San Francisco, in an examination of how eating cooked versus raw food affected gut microbial residents, increasing our understanding of how these microorganisms have evolved with us. The research was published Monday in Nature Microbiology.Carmody has been intrigued by that question since grad school. “Food processing affects the way our bodies digest food,” she points out. “Physical techniques like grinding or pounding can disrupt cells and make their nutrients more accessible. Cooking takes this a step further because in addition to physically transforming food, it chemically transforms it as well.” By processing something that is hard to digest, she said, “You essentially externalize part of the digestive process, and therefore the remaining bits of digestion become more efficient.”Carmody served as first author and co-senior author on the paper along with Peter Turnbaugh, an associate professor of microbiology and immunology and a member of the executive leadership of the UCSF Benioff Center for Microbiome Medicine.The two researchers hypothesized that because cooking increases nutrient absorption in the small intestine, the lesser fraction of nutrients reaching the colon would affect competition among the 100 trillion or so microbes that reside there, leading to downstream effects for the host.To explore the possibilities, Carmody and Turnbaugh first focused on two types of foods that are believed to have provided the bulk of calories during most of human history: meat and starch-rich root vegetables. To test how preparation influences intestinal microbes, they fed mice raw and cooked variants of these foods and measured the resulting changes in gut microbial community composition and function. While the meat eaters’ microbes did not vary much, no matter the preparation, the sweet potato eaters’ did — by quite a lot and within hours. A subsequent experiment in which human participants ate plant-based diets served raw versus cooked confirmed that these effects also held true in human guts.Test subjects’ gut microbiome was altered greatly when they ate raw and cooked sweet potato. Photo courtesy of Rachel CarmodyTo work out the mechanisms driving these gut microbial shifts, the team conducted a range of additional experiments. Follow-up studies in which mice were fed identical chow diets that varied only in the digestibility of the starch component reproduced many of the microbiome changes seen on the raw-versus-cooked-sweet-potato diet, confirming starch digestibility as a key mechanism. Further evidence came from feeding trials using a range of vegetables, which found that the effects of cooking on the gut microbiome were most profound for starchy foods compared with nonstarchy foods like beet and carrot. Researchers also noticed that mice fed raw diets lost weight.Intriguingly, the team also uncovered evidence for a secondary mechanism: heat-induced inactivation of native foodborne antimicrobial compounds.“A growing plant produces a range of antimicrobial compounds to defend itself. When these plant foods are cooked, these compounds are largely inactivated,” Carmody said. “But when these plant foods are eaten raw, some of these antimicrobial compounds act against microbes in the gut — and some microbes are more susceptible than others.”Finally, the researchers transplanted gut microbes from mice fed raw versus cooked plant foods into a group of germ-free mice that were fed a diet of standard chow. The findings were striking and somewhat surprising: the recipients of gut microbes conditioned on raw food gained more weight and body fat than recipients of gut microbes conditioned on cooked food. The raw-food-exposed microbial community had selected for microbes that made the host hungrier and returned more of the energy that the host failed to digest on its own. So although eating raw plants provided less energy overall, associated changes to the microbial community appeared to help make up some of the slack.“Our gut microorganisms not only react to make best use of whatever is available, they’re extraordinarily adaptable,” said Carmody. Rather than evolving over millennia as humans do, the gut microbiome can change in a matter of hours to take advantage of the environment. “That adaptability might be one of the keys to us surviving or developing as a species,” she said.“Until quite recently the human food supply was highly volatile. You had seasonality to worry about. If you went out hunting, you never knew if you would be successful or come back empty-handed. Plasticity in the gut microbiome could have served as an important energetic buffer.” “As a human evolutionary biologist, I’ve reached the point where I’m not totally sure what a human is — where our biology ends and the environment begins.” — Rachel Carmody Is your home making you sick? What we eat and why we eat it Walk this way Related Ph.D. students explore the culture and science of food in the Veritalk podcast The Daily Gazette Sign up for daily emails to get the latest Harvard news.
Published on April 26, 2017 at 9:44 pm Contact Matthew: [email protected] | @MatthewGut21 In 2016, Syracuse’s season ended when Maryland’s Matt Rambo torched the Orange for six points. This year, nobody had picked apart the Syracuse defense the way Rambo did — until Luke Goldstock exploded for three goals and three assists two weeks ago. Goldstock, a versatile senior attack in his third year as a starter for North Carolina, led UNC to a near-upset of the top-ranked Orange on April 15.When North Carolina head coach Joe Breschi described his offense, he focuses on Goldstock. His size and strength, ability to use both hands and off-ball skills mixed with an evolving dodging game helps break down and baffle defenses.The 6-foot-3, 205-pounder has scored 11 goals and added seven assists in five career starts against Syracuse. Goldstock is a versatile playmaker — he can camp behind the cage, set up from outside and get out in transition, posing as one of the most potent threats Syracuse has seen in 2017. The No. 4 seed Tar Heels (6-7, 1-3 Atlantic Coast) need a win to get to .500 and enter the NCAA tournament discussion, and Goldstock could bring them a step closer to doing that. He will present a challenge to the No. 1 seed Orange in the ACC semifinal Friday at 6 p.m. in Durham, North Carolina.“He can see things develop before they happen,” Breschi said. “He’s at the center of our schemes.”Syracuse coaches and players say Goldstock’s greatest strength is his lacrosse IQ. He spaces the field such that he puts teammates in dodging spots and shooters in shooting lanes. SU head coach John Desko said he’s “very smart.” Goldstock easily backs out of space and shoots from distance, too.AdvertisementThis is placeholder textRegardless, he can score in a variety of ways. His three goals against SU two weeks ago, for example, were nothing alike. His first, also UNC’s first of the game, came on a man-up after back-to-back skip passes. Planted to the right of the goal, Goldstock caught a pass, made a quick move and scored.In the images below, Goldstock camps out to the right of Evan Molloy in goal. He’s left alone for a score two passes later. Courtesy ESPNTwo of Goldstock’s assists came from the behind the cage, where he looks for cutters to the crease on a regular basis. Syracuse’s best defender, Scott Firman, matched up on him early in the game. SU threw a variety of looks on him, including brief matchups with Tyson Bomberry, Cunningham and zone looks. It limited Goldstock’s dodging capabilities, but not those without the ball.“We’d slide and it’d be tough for us to get to the second guy,” Bomberry said. “He’d be wide open.”This season, the Tar Heels have pushed transition more than they have in recent years, SU senior midfielder Nick Mariano said. That’s benefited Goldstock, who can get up and down the field and beat midfielders to spots. When he catches the ball, he doesn’t veer away from contact.“He’s an excellent finisher,” Mariano said.Firman said UNC forced Syracuse to rotate to get favorable matchups. Goldstock’s offensive production didn’t come in the form of dodging. Rather, a lot of what he did came off rapid ball movement and inverts. SU changed its slide package in the second half against UNC, which helped turn a 9-1 Tar Heels run into a 7-1 Syracuse run.North Carolina has dropped four straight to Syracuse since the 2015 ACC tournament. Syracuse, riding a nine-game winning streak, has not lost since Feb. 25 and will look for its third consecutive ACC title. If there’s one guy who could help the Tar Heels shift the tides, it’s Goldstock. Comments Courtesy ESPN His second goal came on a one-on-one fake from behind the cage. He faked a pass right, using the cage to create separation between him and SU defender Marcus Cunningham. He darted left and beat SU goalie Evan Molloy for his second score of the day.“It’s very difficult because if you pay too much attention to him off ball, you leave a hole inside,” Desko said. “If you don’t slide to help out, somebody else can come in and swirl by the goaltender.”His third goal came in transition, off a feed from North Carolina close defender Austin Pifani. Running down the left side, Goldstock caught Pifani’s pass, ran straight to the goal and scored from outside of the crease. Cunningham gambled on the pass and paid the price.Below, Goldstock operates from behind the crease, tying up Cunningham and making a move to the goal. Facebook Twitter Google+