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A tomato rich diet may help protect women from breast cancer.From Science Daily:

Diet Rich in Tomatoes May Lower Breast Cancer Risk

A tomato-rich diet may help protect at-risk postmenopausal women from breast cancer, according to new research accepted for publication in The Endocrine Society's Journal of Clinical Endocrinology & Metabolism.Breast cancer risk rises in postmenopausal women as their body mass index climbs. The study found eating a diet high in tomatoes had a positive effect on the level of hormones that play a role in regulating fat and sugar metabolism.

"The advantages of eating plenty of tomatoes and tomato-based products, even for a short period, were clearly evident in our findings," said the study's first author, Adana Llanos, PhD, MPH, who is an Assistant Professor of Epidemiology at Rutgers University. "Eating fruits and vegetables, which are rich in essential nutrients, vitamins, minerals and phytochemicals such as lycopene, conveys significant benefits. Based on this data, we believe regular consumption of at least the daily recommended servings of fruits and vegetables would promote breast cancer prevention in an at-risk population."

The longitudinal cross-over study examined the effects of both tomato-rich and soy-rich diets in a group of 70 postmenopausal women. For 10 weeks, the women ate tomato products containing at least 25 milligrams of lycopene daily. For a separate 10-week period, the participants consumed at least 40 grams of soy protein daily. Before each test period began, the women were instructed to abstain from eating both tomato and soy products for two weeks.

When they followed the tomato-rich diet, participants' levels of adiponectin -- a hormone involved in regulating blood sugar and fat levels -- climbed 9 percent. The effect was slightly stronger in women who had a lower body mass index.

Breast milk contains hundreds of species of bacteria.From the December 8, 2013 Scientific American:

The bacteria in breast milk

Several recent studies have found that breast milk contains a healthy dose of commensal bacteria; all the staphylococci, streptococci, and lactic acid bacteria that are found in the infant gut. This isn’t just bacteria from the skin which have contaminated the samples, but bacteria that have come from inside the breast as an integral component of the milk.

In a study of 16 women it was found that while each milk sample contained hundreds of different bacterial species, around half of the microbiotic community was made up of nine species present in all samples. The other half varied from person to person. This pattern is also found in human gut microbes; a core set present in all individuals along with a large diversity of separate species to make up a unique individual microbiome.

So how do bacteria get into breast milk? Some of them may come from the mouth of the baby. During feeding the skin of both the mother and baby will be in contact with the baby’s open mouth and a certain amount of flow-back can occur between the mouth and nipple. More excitingly it’s been suggested that immune cells in the mothers gut may be able to pick up bacteria and carry them around the body using the lymphatic system. The lymphatic system is a network of vessels used to transport blood plasma. It’s a main highway for immune cells inside the body and is also involved in the absorption and transports of fats.

Like all humans, infants have a range of bacteria within their gut. It looks like these bacteria are initially supplied from the mother’vaginal and skin bacteria, before being replaced by bacteria from the breast milk. Researchers also found that when babies started eating solid food a whole new range of bacteria was introduced, forming the gut microbiome that persisted into adulthood.

From the December 11, 2013 National Geographic:

You Are What You Eat, All 100 Trillion Of You

By setting ten volunteers on either a vegetarian menu or a carnivorous one,Lawrence David from Duke University and Harvard University’s Peter Turnbaugh have shown that when our diet changes, our gut bacteria react very quickly. Within days, some species step into the limelight, while others fade into the background. They activate different genes, pull off different metabolic tricks, and secrete different substances. Our microbiome, it seems, can rapidly switch between plant-eating and meat-eating modes.

David’s team wanted to see what happens over days. If you flood your gut with different food, how long does it take for your microbiome to react?

They did this by recruiting ten volunteers who were willing to collect daily faecal samples. They each ate two different diets for five straight days —a plant-based one that was rich in grains, legumes, fruit and vegetables, and an animal-based one composed of meat, eggs and cheese.

In general, the animal diet led to more dramatic changes than the plant one. 

David and Turnbaugh’s team also found that the altered gut communities did different things. During the plant diet, they became better at breaking down carbohydrates; during the animal diet, protein digestion was their forte. On the meat-heavy days, they activated more genes for breaking down harmful chemicals found in charred meat, and for making vitamins.

And these changes happened very quickly. Some were obvious by day one. By day four, you could pick up a stool sample, list the active genes within it, and predict with total accuracy which diet the owners had been on.

Just two days after the volunteers stopped their diets, things were back to normal. The gut microbiome, it seems, is a fickle beast—easily changed, but not permanently so. The team also found that our food doesn’t just change the microbes that already exist in the gut—they also add some new ones. 

The point is that our gut microbiomes are more flexible than we previously thought. A recent study showed that most of the strains in our guts stay there for decades or more. But while the roster is clearly stable, their relative numbers fluctuate a lot, and food-borne newcomers can gain a foothold.

In case you missed it, Michael Pollan wrote an article about the human microbiome (the community of microbes that live within us) that was published May 15, 2013. Much of the article was about how the modern western diet may not be good for the human microbiome and how we can eat for better gut health. From the NY Times:

Some of My Best Friends Are Germs 

 As part of a new citizen-science initiative called thAmerican Gut project, the lab sequenced my microbiome — that is, the genes not of “me,” exactly, but of the several hundred microbial species with whom I share this body. These bacteria, which number around 100 trillion, are living (and dying) right now on the surface of my skin, on my tongue and deep in the coils of my intestines, where the largest contingent of them will be found, a pound or two of microbes together forming a vast, largely uncharted interior wilderness that scientists are just beginning to map.

Few of the scientists I interviewed had much doubt that the Western diet was altering our gut microbiome in troubling ways. Some, like Blaser, are concerned about the antimicrobials we’re ingesting with our meals; others with the sterility of processed food. Most agreed that the lack of fiber in the Western diet was deleterious to the microbiome, and still others voiced concerns about the additives in processed foods, few of which have ever been studied for their specific effects on the microbiota.

So I gave up asking scientists for recommendations and began asking them instead how, in light of what they’ve learned about the microbiome, they have changed their own diets and lifestyles. Most of them have made changes. They were slower to take, or give their children, antibiotics. (I should emphasize that in no way is this an argument for the rejection of antibiotics when they are medically called for.) Some spoke of relaxing the sanitary regime in their homes, encouraging their children to play outside in the dirt and with animals — deliberately increasing their exposure to the great patina. Many researchers told me they had eliminated or cut back on processed foods, either because of its lack of fiber or out of concern about additives. In general they seemed to place less faith in probiotics (which few of them used) than in prebiotics — foods likely to encourage the growth of “good bacteria” already present. Several, including Justin Sonnenburg, said they had added fermented foods to their diet: yogurt, kimchi, sauerkraut. These foods can contain large numbers of probiotic bacteria, like L. plantarum and bifidobacteria, and while most probiotic bacteria don’t appear to take up permanent residence in the gut, there is evidence that they might leave their mark on the community, sometimes by changing the gene expression of the permanent residents — in effect turning on or off metabolic pathways within the cell — and sometimes by stimulating or calming the immune response.

...something a gastroenterologist at the University of Pittsburgh told me. “The big problem with the Western diet,” Stephen O’Keefe said, “is that it doesn’t feed the gut, only the upper G I. All the food has been processed to be readily absorbed, leaving nothing for the lower G I. But it turns out that one of the keys to health is fermentation in the large intestine.” And the key to feeding the fermentation in the large intestine is giving it lots of plants with their various types of fiber, including resistant starch (found in bananas, oats, beans); soluble fiber (in onions and other root vegetables, nuts); and insoluble fiber (in whole grains, especially bran, and avocados).

With our diet of swiftly absorbed sugars and fats, we’re eating for one and depriving the trillion of the food they like best: complex carbohydrates and fermentable plant fibers. The byproduct of fermentation is the short-chain fatty acids that nourish the gut barrier and help prevent inflammation. And there are studies suggesting that simply adding plants to a fast-food diet will mitigate its inflammatory effect.

...I began to see how you might begin to shop and cook with the microbiome in mind, the better to feed the fermentation in our guts. The less a food is processed, the more of it that gets safely through the gastrointestinal tract and into the eager clutches of the microbiota. Al dente pasta, for example, feeds the bugs better than soft pasta does; steel-cut oats better than rolled; raw or lightly cooked vegetables offer the bugs more to chomp on than overcooked, etc. This is at once a very old and a very new way of thinking about food: it suggests that all calories are not created equal and that the structure of a food and how it is prepared may matter as much as its nutrient composition.