Food preservatives linked to obesity and gut disease : Nature News & Comment

Food preservatives linked to obesity and gut disease : Nature News & Comment

Artificial preservatives used in many processed foods could increase the risk of inflammatory bowel diseases and metabolic disorders, according to research published on 25 February in Nature1. In a study done in mice, chemicals known as emulsifiers were found to alter the make-up of bacteria in the colon — the first time that these additives have been shown to affect health directly.

About 15 different emulsifiers are commonly used in processed Western foods for purposes such as smoothing the texture of ice cream and preventing mayonnaise from separating. Regulatory agencies such as the US Food and Drug Administration (FDA) rule that emulsifiers are “generally regarded as safe”, because there is no evidence that they increase the risk of cancer or have toxic effects in mammals.

via Food preservatives linked to obesity and gut disease : Nature News & Comment.

Gut Microbiota Influences Blood Brain Barrier Permeability | Neuroscience News Research Articles | Neuroscience Social Network

The more I read about the microbiome..Amazing stuff.

A new study in mice, conducted by researchers at Sweden’s Karolinska Institutet together with colleagues in Singapore and the United States, shows that our natural gut-residing microbes can influence the integrity of the blood-brain barrier, which protects the brain from harmful substances in the blood. According to the authors, the findings provide experimental evidence that our indigenous microbes contribute to the mechanism that closes the blood-brain barrier before birth. The results also support previous observations that gut microbiota can impact brain development and function.

The blood-brain barrier is a highly selective barrier that prevents unwanted molecules and cells from entering the brain from the bloodstream. In the current study, being published in the journal Science Translational Medicine, the international interdisciplinary research team demonstrates that the transport of molecules across the blood-brain barrier can be modulated by gut microbes – which therefore play an important role in the protection of the brain.

via Gut Microbiota Influences Blood Brain Barrier Permeability | Neuroscience News Research Articles | Neuroscience Social Network.

How Bacteria In The Gut Help Fight Off Viruses : Goats and Soda : NPR

So what is this magic antiviral bullet?

It’s those hairlike threads that dangle off some bacteria and help them swim. Yup, that’s right, the flagella.

When Gewirtz and his team injected pieces of the flagella under the mice’s skin, a part of the immune system kicked into action and stopped the rotavirus infection dead in its tracks.But these bacteria — and their flagella — are in our gut. Would they still be able to talk to the immune system? Hooper thinks so. Here’s why.

Just like our hair, flagella are constantly falling off the surfaces of bacteria as they swim around in the gut. “Cool immune cells, called dendritic cells, are constantly surveying what’s going on in the body,” Hooper says. They can bind to the pieces of flagella in the gut and then mobilize other immune cells to come and fight the viral infection.

via How Bacteria In The Gut Help Fight Off Viruses : Goats and Soda : NPR.

Modern Medicine May Not Be Doing Your Microbiome Any Favors: NPR

According to Dr. Martin Blaser, the overuse of antibiotics has contributed to killing off strains of bacteria that typically live in the gut.

According to Dr. Martin Blaser, the overuse of antibiotics has contributed to killing off strains of bacteria that typically live in the gut.

Joe Raedle/Getty Images

There are lots of theories about why food allergies, asthma, celiac disease and intestinal disorders like Crohn’s disease have been on the rise. Dr. Martin Blaser speculates that it may be connected to the overuse of antibiotics, which has resulted in killing off strains of bacteria that typically live in the gut.

Blaser is an expert on the human microbiome, which is the collection of bacteria, viruses, fungi and other microbes that live in and on the body. In fact, up to 90 percent of all the cells in the human body aren’t human at all — they’re micro-organisms.

Blaser is the director of NYU’s Human Microbiome Program and a former chairman of medicine there. His new book is called Missing Microbes: How the Overuse of Antibiotics Is Fueling Our Modern Plagues.

Missing Microbes
 
Missing Microbes

How the Overuse of Antibiotics Is Fueling Our Modern Plagues

by Martin Blaser

He tells Fresh Air‘s Terry Gross that with the overuse of antibiotics, as well as some other now-common practices like cesarean sections, we’ve entered a danger zone — a no man’s land between the world of our ancient microbiome and an uncharted modern world.


Interview Highlights

On why he thinks the number of diseases has risen

Since World War II, we’ve seen big rises in a number of diseases: asthma, allergies, food allergies, wheat allergy, juvenile diabetes, obesity. … These are all diseases that have gone up dramatically in the last 50 or 70 years. One of the questions is: Why are they going up? Are they going up for 10 different reasons, or perhaps there is one reason that is fueling all of them.

My theory is that the one reason is the changing microbiome; that we evolved a certain stable situation with our microbiome and with the modern advances of modern life, including modern medical practices, we have been disrupting the microbiome. And there’s evidence for that, especially early in life, and it’s changing how our children develop.

On the potential link between antibiotics and obesity

We have experiments in mice where, since we’re very interested in obesity, if we put mice on a high-fat diet, they gain weight; they get fat. If we put them on antibiotics early in life, they also get fat. If we put [them] on both together, they get very fat. … It’s clear that the effects of the antibiotics potentiate the effects of the high-fat diet. We’re not letting [the] high-fat diet off the hook, we’re saying that there’s another factor there. …

There’s a choreography; there’s a normal developmental cycle of the microbiome from birth over the first few years of life, especially the first three years, [that] appear[s] to be the most important. And that’s how nature has, how we have, evolved together so that we can maximize health and create a new generation, which is nature’s great purpose. And because of modern practices, we have disrupted that. And then the question is: Does that have consequence[s]? Our studies in mice show that it does have consequences. We’ve done epidemiologic studies in people that show that some of these modern practices are increasing the risk of obesity as well.

On how the birth process informs a baby’s microbiome

As far as we know, when the baby is inside the womb it is apparently sterile. … The big moment of truth is when the membranes rupture, the water breaks, and the baby starts coming out. And that’s where they first get exposed to the bacteria of the world, and the first bacteria they’re exposed to is their mother’s bacteria in the birth canal. So as labor proceeds, the babies are in contact with the microbes lining their mother’s vagina and, as they’re going out, they’re covered by these bacteria. They swallow the bacteria; it’s on their skin. …

That’s their initial exposure to the world of bacteria. That’s how mammals have been doing it for the last 150 million years, whether they’re dolphins or elephants or humans. … And we know a little about what those bacteria are. The most common bacteria are lactobacillus and there’s evidence that over the course of pregnancy the microbiome in the vagina changes, just as many other parts of the body are changing. The microbiome is changing in its composition in terms of maximizing lactobacilli, and these are bacteria that eat lactose, which is the main component of milk. So the baby’s mouth is filled with lactobacilli. The first thing that happens is they go up against their mom’s breast and they inoculate the nipple with lactobacilli and now milk and lactobacilli go into the new baby and that’s the foundation for their microbiome and that’s how they start their life. …

You could project that if they didn’t acquire these organisms or they didn’t acquire them normally or at the normal time, then the foundations might be a little shaky.

On a study comparing the microbiomes of babies born via C-section and those born vaginally

Shortly after birth, they compared the microbiomes in the babies that came out. The babies that were born vaginally, their microbiome, not surprisingly, looked like the mom’s vagina everywhere in the body — in their GI tract, on their skin, in their mouth. But the babies born by C-section, their microbiome looked like skin and it didn’t even necessarily look like the mom’s skin, maybe it was somebody else in the operating room. So it’s clear that the microbiome is different immediately depending on the kind of birth.

There have been more and more epidemiologic studies asking the question, really for the first time: Are there long-term health consequences of being born by C-section?

 

On how the microbiome can determine a person’s immunity and allergies

I’m concerned that the microbiome is part of our whole developmental process and if we disrupt it early, there are potentially consequences. …

What I can tell you is that our immune system is quite complex. There are many kinds of immune cells. There are cells that strongly recognize foreign substances, there are ones that try to damp [the immune system] and down-regulate it. There’s what we call innate immunity, which is the immunity we’re all born with, and then there’s adaptive immunity — the immunity that develops when we experience different kinds of exposures. So it’s very complex.

It’s developing early in life. That’s what sets, in essence, [the] immunological tone that will determine how allergic a person is, or how stoical a person is in an immunologic sense.

On probiotics

There are many different probiotics. If you go to the grocery store, the health food store, the drugstore, there are shelves and shelves full of probiotics [with] different names, different compositions. I think I can say three things: The first is that they’re almost completely unregulated; second is that they seem to be generally safe; and third is that they’re mostly untested. …

Right now, it’s the Wild West. I’m actually a big believer in probiotics; I think that’s going to be part of the future of medicine, that we’re going to understand the science of the microbiome well enough so that we can look at a sample from a child and say this child is lacking such-and-such an organism and now we’re going to take it off the shelf and we’re going to give it back to that child. … Just as today the kids are lining up for the vaccines, in the future, maybe the kids are going to be drinking certain organisms so that we can replace the ones that they’ve lost.

Chocolate-Loving Gut Microbes Turn Cocoa Into Heart-Healthy Molecules : The Salt : NPR

Thank Your Gut Bacteria For Making Chocolate Healthful

by MICHAELEEN DOUCLEFF

March 18, 2014 2:31 PM

Bacteria in your gut can break down the antioxidants in chocolate into smaller, anti-inflammatory compounds.

Boy, it’s a good time to be a dark-chocolate lover.

We’ve noted before the growing evidence that a daily dose of the bitter bean may help reduce blood pressure. There also seems to be a link between a regular chocolate habit and lower body weight.

Now scientists are offering an explanation for just why cocoa powder may be good for the heart and waistline. The magic may reside in our microbes.

The friendly bacteria in our guts can gobble up cocoa powder and turn it into compounds known to help the heart, food scientists from Louisiana State University reported Tuesday at the American Chemical Society meeting in Dallas.

The critters also convert the cocoa powder into molecules that reduce inflammation and help tell us when we’re full.

“These are good compounds to have in your gut,” says John Finley, who led the study. “They can get absorbed into your blood” and protect cells in your blood vessels from stress, he says.

For centuries, people have been attributing a vast array of health benefits to eating chocolate, from curing infertility and fatigue to fever and dental problems. But so far, the links to lower blood pressure and heart health have been the strongest — and one of the few benefits to pass muster in the eyes of science.

“I was holding out for scientists to prove chocolate’s aphrodisiac effect,” Finley jokes. “But it’s the cardiovascular benefits that will probably pan out. Our findings are one more brick in the road to proving that one.”

Of course, Finley is talking about cocoa powder here: The stuff that has no sugar and milk in it. “Our results don’t translate to a Hershey bar,” he says. “But cocoa powder goes well with many foods. I put it on my oatmeal every morning with berries.”

Cocoa powder is packed with potent antioxidants, called polyphenols. These healthful molecules are also found in dark berries and black tea. And they’re known to help the heart and possibly prevent cancer.

But there’s one major problem with many polyphenols: They’re so large that they don’t get absorbed into the blood. That’s where the critters in your gut can help out, Finley says.

Previous studies have found that gut bacteria like to feast on polyphenols from blackberries and tea. So Finley wanted to see what the bugs would do with the polyphenols in cocoa powder.

The Salt

Chowing Down On Meat, Dairy Alters Gut Bacteria A Lot, And Quickly

He and his students passed the cocoa powder through a device that mimics the human gut. First, it treats the cocoa with enzymes like the ones in your stomach. And then the remaining material goes through an “artificial colon.”

“It’s a rather yucky way of mimicking people’s lower gut,” Finely says. “It’s just a mixture of fecal matter. We pay people $20 to give us a sample. We get a lot of graduate students to volunteer.”

Sounds gross, but those “donations” are teeming with life — trillions of bacteria that see the cocoa powder as a five-star dinner.

“The microbes break down the polyphenols into smaller molecules that are more likely to make it across the gut into the blood,” Finely says. Those compounds are the good ones that help reduce inflammation and stress in the blood vessels.

And the friendly bacteria don’t stop there. They also feasted on the fiber in cocoa powder, Finley and his team found. “The microbes break down the fiber into short fatty chain acids, which get absorbed and can have an effect on satiety,” he says.

Of course, Finley and his team have to confirm their results in real digestive tracts. “The next step is to give people cocoa powder and see if we can find these metabolites in the blood,” he says.

Those types of experiments are critical to figuring out exactly what’s in chocolate that makes it healthy for the heart, says Joshua Lambert, a food scientist at Pennsylvania State University, who wasn’t involved in the study.

“That’s the big missing link right now,” Lambert tells The Salt. We know now that gut bacteria can break down cocoa into compounds that have beneficial cardiovascular effects, he says. But we don’t know yet if these are the critical ones inside the blood.

In the meantime, I’ll keep indulging my gut bacteria with a few cubes of extra dark chocolate each day. Seems like a win-win situation for both of us.

via Chocolate-Loving Gut Microbes Turn Cocoa Into Heart-Healthy Molecules : The Salt : NPR.