Daniel Charles

There's a part of our body that's only now getting mapped: the trillions of microbes, mostly bacteria, that live in our guts.

Some scientists describe this community as a previously unnoticed vital organ. It appears to play a role in how quickly we gain weight and how well we fight off disease.

A study published in the journal Science suggests that changes in this community of microbes also may cause kwashiorkor, a kind of deadly malnutrition.

Take a look at this remarkable graph — is it the stock market? Home sales?

Nope. Click on the blue box in the lower right-hand corner and you'll see that the blue line tracks the number of chicken wings that Americans bought at grocery stores over the last year. See that mighty surge of wing-buying in early February? Apparently, you just cannot have a Super Bowl party without chicken wings — millions and millions of chicken wings.

Many big food companies are caught in a dilemma these days. They want to rebrand themselves as merchants of health — Coca-Cola's new anti-obesity ads are just the latest example — but many of their profits still come from products that make nutritionists scowl.

If there's one person who symbolizes this tension, it's Derek Yach.

For years, the biotech giant Monsanto has provoked outrage among its critics for suing farmers who save and replant seeds, such as soybeans and canola, from the company's patented Roundup Ready crops.

It's amazing how many different kinds of people have been trying to abolish or at least change the government's payments to farmers. They include economists, environmentalists, taxpayer advocates, global anti-hunger advocates and even a lot of farmers. Some have been fighting farm subsidies for the past 20 years.

This past year, those critics laid siege to offices on Capitol Hill because the law that authorizes these programs — the farm bill — was about to expire. (It has to be renewed every five years.)

Now that the Christmas feast is over, you may be looking at all the extra food you made, or the food that you brought home from the store that never even got opened.

And you may be wondering: How long can I keep this? What if it's past its expiration date? Who even comes up with those dates on food, anyway, and what do they mean?

Here's the short answer: Those "sell by" dates are there to protect the reputation of the food. They have very little to do with food safety. If you're worried whether food is still OK to eat, just smell it.

Nobody really wants to think about economics, the famously dismal science, while sitting down at a table loaded with love and calories. Like it or not, though, supply and demand drive food production and set the price of dinner.

So, in a season of feasts, what are the business stories on your holiday menu?

Have you noticed, perhaps, that some of your store-bought salad dressings or spaghetti sauces taste a little less salty lately?

Probably not. The companies that make those products are doing their best to keep you from noticing. Yet many of them are, in fact, carrying out a giant salt-reduction experiment, either because they want to improve their customers' health or because they're worried that if they don't, the government might impose regulations that would compel more onerous salt reductions.

Salt is one of those dangerously tasty substances. We add the magical crystals of sodium chloride to almost everything that we cook or bake, and according to many public health experts, we add too much.

They want us to cut back, to lower our risk of heart attacks or strokes.

Yet when you really start looking for ways to do this, you run into a paradox and a scientific puzzle.

First, the paradox. Too much salt may kill us, but our bodies need some of it to survive.

If you're looking for a dash of optimism about the future — and who isn't, these days? — you can find it in a rosy new prediction about the planet's ability to produce food for the next half-century.

A few days ago, two big names in food policy squared off for a formal debate on the following proposition: There is a fundamental and irreconcilable conflict between the food and beverage industry's interests and public health policy interests on obesity.

A few months ago, I let you in on a little secret about Greek yogurt. Not all of this extra-thick, protein-rich yogurt is made the old-style way, by straining liquid out of it it. Some companies are creating that rich taste by adding thickeners, such as powdered protein and starch.

French adventurer-scientist Roland Bourdeix has a grand, almost surreal, vision for how to preserve a thousand or more genetic varieties of coconut trees. Imagine, as he does, turning dozens or hundreds of remote Pacific islands into coconut sanctuaries. Each island would contain just a few varieties of these trees. No others would be allowed, because the whole point of this exercise is to prevent uncontrolled mixing of genes from different varieties.

The ethanol industry is happy with the Environmental Protection Agency today. If you're worried about the price of meat, though, you may not be so pleased.

If you've ever checked the ingredient list on a PowerBar or a high-protein smoothie, you probably have stumbled across these words: "Whey protein concentrate." You'll find it in a growing number of prepared foods.

This mysterious ingredient is derived from one of the oldest of human foods — milk. But capturing it requires huge factories that look more like oil refineries than farms.

The Food and Drug Administration has confirmed that it received five reports in the past past three years suggesting that people died after drinking caffeinated energy drinks.

But the agency also cautions that these reports do not add up to proof that the beverages actually caused those deaths. These reports — called adverse event reports — are considered unconfirmed allegations, and the FDA doesn't usually release them.

It's not just nutritionists who have a problem with sugar these days, so does organized labor. The AFL-CIO is calling for a boycott of one the country's biggest sugar producers, the American Crystal Sugar Company, based in Moorhead, Minn.

Having just stepped into the shouting match over patents on genetically engineered crops, there are a few small things that I, too, would like to get off my chest.

Why do so many people hate Monsanto?

Is it because this multinational corporation pioneered some enormously successful genetically engineered crops, including corn, soybeans and cotton?

Here's an astonishing fact: Half of America's mushrooms are grown in one tiny corner of southeastern Pennsylvania, near the town of Kennett Square.

But why? It's not as though this place has some special advantage of climate or soil, the kind of thing that led to strawberry fields in Watsonville, Calif., or peach orchards in Georgia. Mushrooms can grow indoors. They could come from anywhere.