{"id":7954,"date":"2020-11-30T12:25:41","date_gmt":"2020-11-30T17:25:41","guid":{"rendered":"https:\/\/cals.ncsu.edu\/applied-ecology-new\/?p=7954"},"modified":"2020-11-30T12:39:30","modified_gmt":"2020-11-30T17:39:30","slug":"basic-bear-bowels-beget-barren-gut-biomes","status":"publish","type":"post","link":"https:\/\/cals.ncsu.edu\/applied-ecology\/news\/basic-bear-bowels-beget-barren-gut-biomes\/","title":{"rendered":"Basic Bear Bowels Beget Barren Gut Biomes"},"content":{"rendered":"

This post is an adaptation of a news release prepared by Matt Shipman – click here to view the entire release<\/a> from NC State News.<\/em><\/p>\n

Scientists have discovered that being a carnivore doesn’t require as many guts as previously thought.<\/p>\n

While most mammals\u2019 guts are a string of surprisingly complex and distinct environments, scientists have now learned that black bears appear to be an exception, with its gut playing host to a microbial population that varies little across the intestinal tract.<\/span><\/p>\n

\"A
A schematic of the two areas sampled in bear guts for this study. Used with permission of Sierra J. Gillman<\/figcaption><\/figure>\n

\u201cIt\u2019s the first mammal species where we\u2019ve looked at two separate locations in the gut and found microbial communities that are essentially indistinguishable from each other,\u201d says Sierra Gillman<\/a>, first author of a paper on the work and a Ph.D. student at the University of Washington. Gillman did the work while a grad student at Northern Michigan University (NMU).<\/span><\/p>\n

\u201cBears have really simple guts \u2013\u00a0pretty much a garden hose \u2013\u00a0so they can\u2019t regulate their gut microbes to the extent that animals with longer, more complex guts can,\u201d says Erin McKenney<\/a>, co-author of the paper and an assistant professor of applied ecology<\/a> at North Carolina State University. \u201cWithout that control, the bears\u2019 diet and environment may play a greater role in shaping the gut microbiome. It raises some interesting evolutionary questions about the relationship between the shape of an animal\u2019s gut, its gut microbiome, and the relationship between the microbiome and the animal\u2019s health and behavior.\u201d<\/span><\/p>\n

The researchers set out to learn more about the gut microbiome of American black bears (<\/span>Ursus americanus<\/span><\/i>) with little idea of what to expect. Not much research has been done on microbial ecosystems in the species, and what work has been done has focused on animals in captivity. Since animals in captivity and animals in the wild often have very different gut microbiomes, the researchers were curious as to what they\u2019d find. One major challenge was obtaining samples in the first place.<\/span><\/p>\n

\"The
The bear gut collection protocol sheet distributed to guides by Gillman et al.<\/figcaption><\/figure>\n

To that end, the researchers worked collaboratively with guides who lead scheduled hunting trips in the Upper Peninsula of Michigan. Gillman developed a detailed set of protocols (pictured right) and conducted gut sample training sessions with the guides. Specifically, Gillman taught the guides how to retrieve samples from both the jejunum, which is the middle section of the small intestine, and the colon, which is also called the large intestine (see schematic above).\u00a0<\/span><\/p>\n

Ultimately, the researchers obtained 31 useable jejunum samples and 30 useable colon samples. They then analyzed the samples to identify which microbial species were present.<\/span><\/p>\n

The researchers expected to see more, and different, species of microbes in the colon. The colon is often where digestion slows down, enabling gut microbes to break down fiber in the diet \u2013 which normally fosters microbial diversity. But not, apparently, in the black bears of Michigan.<\/span><\/p>\n

Why are bear gut microbiomes different from the microbiomes of other omnivores scientists have looked at? In a word, it\u2019s probably the cecum.<\/span><\/p>\n

Omnivores with more complex guts have a small pouch \u2013 called the cecum \u2013 between the small and large intestine. The cecum helps slow down the rate at which food passes through the gut, like an oxbow in a river, and likely serves as a reservoir for microbial populations in the gut, allowing animals to replenish the diversity of their microbiomes, even as their diets and health change.<\/span><\/p>\n

\u201cBears don\u2019t have a cecum,\u201d Gillman says. \u201cThat makes their gut microbiomes more vulnerable to systemic change due to diet, health or other factors.\u201d<\/span><\/p>\n

This finding has an immediate practical application for wildlife researchers.<\/span><\/p>\n

\u201cIn many animal species, a fecal sample can tell you what the microbial diversity of the colon was like \u2013 but it doesn\u2019t tell you much about what\u2019s happening in other parts of the gut,\u201d says Diana Lafferty<\/a>, co-author of the paper and an assistant professor of wildlife ecology at NMU. \u201cOur work suggests that a fecal sample offers insight into the microbial community across the entire gut for black bears \u2013 and possibly for other carnivores and omnivores that have simple gut morphologies.\u201d<\/span><\/p>\n

In other words, we can learn more from wild animal poop than previously thought.<\/span><\/p>\n

The researchers are currently in the process of comparing the samples collected in Michigan to samples from black bears harvested by hunters in North Carolina, in order to determine if the findings are consistent across geographic regions.<\/span><\/p>\n

\u201cWe are also looking at carnivore species that also lack a cecum to see if they have a similar lack of microbial diversity across the gut,\u201d Gillman says.<\/span><\/p>\n

\u201cAnd we are working on a project that will help us better identify and understand the connections between the gut microbiome and bear health,\u201d says Lafferty.<\/span><\/p>\n

\u201cOne of the things we\u2019re curious about is weight gain,\u201d McKenney says. \u201cWe know that specific shifts in the microbiome can lead to weight gain and obesity in other species, which is usually viewed as a negative. But for species that hibernate, like bears, that could actually be advantageous.\u201d<\/span><\/p>\n

The paper, \u201c<\/span>Wild black bears harbor simple gut microbial communities with little difference between the jejunum and colon<\/span><\/a>,\u201d appears open access in the journal <\/span>Scientific Reports<\/span><\/i>.<\/span><\/p>\n","protected":false,"raw":"This post is an adaptation of a news release prepared by Matt Shipman - click here to view the entire release<\/a> from NC State News.<\/em>\r\n\r\nScientists have discovered that being a carnivore doesn't require as many guts as previously thought.\r\n\r\nWhile most mammals\u2019 guts are a string of surprisingly complex and distinct environments, scientists have now learned that black bears appear to be an exception, with its gut playing host to a microbial population that varies little across the intestinal tract.<\/span>\r\n\r\n[caption id=\"attachment_7963\" align=\"alignright\" width=\"251\"]\"A A schematic of the two areas sampled in bear guts for this study. Used with permission of Sierra J. Gillman[\/caption]\r\n\r\n\u201cIt\u2019s the first mammal species where we\u2019ve looked at two separate locations in the gut and found microbial communities that are essentially indistinguishable from each other,\u201d says Sierra Gillman<\/a>, first author of a paper on the work and a Ph.D. student at the University of Washington. Gillman did the work while a grad student at Northern Michigan University (NMU).<\/span>\r\n\r\n\u201cBears have really simple guts \u2013\u00a0pretty much a garden hose \u2013\u00a0so they can\u2019t regulate their gut microbes to the extent that animals with longer, more complex guts can,\u201d says Erin McKenney<\/a>, co-author of the paper and an assistant professor of applied ecology<\/a> at North Carolina State University. \u201cWithout that control, the bears\u2019 diet and environment may play a greater role in shaping the gut microbiome. It raises some interesting evolutionary questions about the relationship between the shape of an animal\u2019s gut, its gut microbiome, and the relationship between the microbiome and the animal\u2019s health and behavior.\u201d<\/span>\r\n\r\nThe researchers set out to learn more about the gut microbiome of American black bears (<\/span>Ursus americanus<\/span><\/i>) with little idea of what to expect. Not much research has been done on microbial ecosystems in the species, and what work has been done has focused on animals in captivity. Since animals in captivity and animals in the wild often have very different gut microbiomes, the researchers were curious as to what they\u2019d find. One major challenge was obtaining samples in the first place.<\/span>\r\n\r\n[caption id=\"attachment_7957\" align=\"alignright\" width=\"460\"]\"The The bear gut collection protocol sheet distributed to guides by Gillman et al.[\/caption]\r\n\r\nTo that end, the researchers worked collaboratively with guides who lead scheduled hunting trips in the Upper Peninsula of Michigan. Gillman developed a detailed set of protocols (pictured right) and conducted gut sample training sessions with the guides. Specifically, Gillman taught the guides how to retrieve samples from both the jejunum, which is the middle section of the small intestine, and the colon, which is also called the large intestine (see schematic above).\u00a0<\/span>\r\n\r\nUltimately, the researchers obtained 31 useable jejunum samples and 30 useable colon samples. They then analyzed the samples to identify which microbial species were present.<\/span>\r\n\r\nThe researchers expected to see more, and different, species of microbes in the colon. The colon is often where digestion slows down, enabling gut microbes to break down fiber in the diet \u2013 which normally fosters microbial diversity. But not, apparently, in the black bears of Michigan.<\/span>\r\n\r\nWhy are bear gut microbiomes different from the microbiomes of other omnivores scientists have looked at? In a word, it\u2019s probably the cecum.<\/span>\r\n\r\nOmnivores with more complex guts have a small pouch \u2013 called the cecum \u2013 between the small and large intestine. The cecum helps slow down the rate at which food passes through the gut, like an oxbow in a river, and likely serves as a reservoir for microbial populations in the gut, allowing animals to replenish the diversity of their microbiomes, even as their diets and health change.<\/span>\r\n\r\n\u201cBears don\u2019t have a cecum,\u201d Gillman says. \u201cThat makes their gut microbiomes more vulnerable to systemic change due to diet, health or other factors.\u201d<\/span>\r\n\r\nThis finding has an immediate practical application for wildlife researchers.<\/span>\r\n\r\n\u201cIn many animal species, a fecal sample can tell you what the microbial diversity of the colon was like \u2013 but it doesn\u2019t tell you much about what\u2019s happening in other parts of the gut,\u201d says Diana Lafferty<\/a>, co-author of the paper and an assistant professor of wildlife ecology at NMU. \u201cOur work suggests that a fecal sample offers insight into the microbial community across the entire gut for black bears \u2013 and possibly for other carnivores and omnivores that have simple gut morphologies.\u201d<\/span>\r\n\r\nIn other words, we can learn more from wild animal poop than previously thought.<\/span>\r\n\r\nThe researchers are currently in the process of comparing the samples collected in Michigan to samples from black bears harvested by hunters in North Carolina, in order to determine if the findings are consistent across geographic regions.<\/span>\r\n\r\n\u201cWe are also looking at carnivore species that also lack a cecum to see if they have a similar lack of microbial diversity across the gut,\u201d Gillman says.<\/span>\r\n\r\n\u201cAnd we are working on a project that will help us better identify and understand the connections between the gut microbiome and bear health,\u201d says Lafferty.<\/span>\r\n\r\n\u201cOne of the things we\u2019re curious about is weight gain,\u201d McKenney says. \u201cWe know that specific shifts in the microbiome can lead to weight gain and obesity in other species, which is usually viewed as a negative. But for species that hibernate, like bears, that could actually be advantageous.\u201d<\/span>\r\n\r\nThe paper, \u201c<\/span>Wild black bears harbor simple gut microbial communities with little difference between the jejunum and colon<\/span><\/a>,\u201d appears open access in the journal <\/span>Scientific Reports<\/span><\/i>.<\/span>"},"excerpt":{"rendered":"

Scientists have discovered that being a carnivore doesn’t require as many guts as previously thought.\u00a0<\/p>\n","protected":false},"author":2094,"featured_media":7955,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"source":"","ncst_custom_author":"","ncst_show_custom_author":false,"ncst_dynamicHeaderBlockName":"","ncst_dynamicHeaderData":"","ncst_content_audit_freq":"","ncst_content_audit_date":"","footnotes":"","_links_to":"","_links_to_target":""},"categories":[7,8,3,5],"tags":[],"class_list":["post-7954","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-faculty-and-staff","category-faculty-focus","category-impact","category-research"],"displayCategory":null,"acf":[],"_links":{"self":[{"href":"https:\/\/cals.ncsu.edu\/applied-ecology\/wp-json\/wp\/v2\/posts\/7954","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/cals.ncsu.edu\/applied-ecology\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/cals.ncsu.edu\/applied-ecology\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/cals.ncsu.edu\/applied-ecology\/wp-json\/wp\/v2\/users\/2094"}],"replies":[{"embeddable":true,"href":"https:\/\/cals.ncsu.edu\/applied-ecology\/wp-json\/wp\/v2\/comments?post=7954"}],"version-history":[{"count":5,"href":"https:\/\/cals.ncsu.edu\/applied-ecology\/wp-json\/wp\/v2\/posts\/7954\/revisions"}],"predecessor-version":[{"id":7972,"href":"https:\/\/cals.ncsu.edu\/applied-ecology\/wp-json\/wp\/v2\/posts\/7954\/revisions\/7972"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/cals.ncsu.edu\/applied-ecology\/wp-json\/wp\/v2\/media\/7955"}],"wp:attachment":[{"href":"https:\/\/cals.ncsu.edu\/applied-ecology\/wp-json\/wp\/v2\/media?parent=7954"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cals.ncsu.edu\/applied-ecology\/wp-json\/wp\/v2\/categories?post=7954"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cals.ncsu.edu\/applied-ecology\/wp-json\/wp\/v2\/tags?post=7954"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}