Your 'belly bug' supplement is useless without this

Not too long ago, "probiotics" was a funny-sounding word that most folks had never heard of.

These days, you've not only heard of it. You're probably taking one!

And if you aren't, heading into the winter is a good time to get started. These helpful bacteria can do more than ease digestion -- they can bolster your immune system to prevent nasty winter infections.

But don't stop with a good probiotic supplement.

New research shows that there's another piece of the puzzle -- something that can help ensure that those probiotic bacteria take hold in your gut and thrive to give you maximum protection.

You need essential omega-3 fatty acids.

The study of older women finds the more of these inflammation-fighting essential oils you have in your system, the happier and healthier your gut bacteria will be.

Higher omega-3 levels in both the diet and blood lead to greater diversity in your gut.

That's just what it sounds like: a wide range of different types of bacteria, which studies show can help boost your overall health and even increase your longevity.

You can't get that from a supplement alone.

You need to have the conditions down there that allow all those colonies to thrive -- and the new study finds omega-3s will do just that.

Boost your own levels, and your gut will be more diverse than the New York City subway!

The study finds that the higher the levels of omega-3 in your blood, the more likely you'll have specific strains of bacteria known to fight inflammation... control your weight... and prevent disease.

High levels of omega-3s can even increase a compound in your gut called N-carbamylglutamate, which can fight damaging oxidative stress.

Most of the women in the study who had high omega-3 levels got it from diet, which means they were likely eating plenty of fatty fish such as salmon, trout, and tuna.

But some people don't like fish, or they just don't eat enough of it (and when you see the price of salmon these days, it's not hard to see why).

In that case, make sure you're taking a decent omega-3 supplement with high levels of both EPA and DHA together with a quality probiotic.

Along with boosting your health, probiotics can prevent urinary infections... ease constipation... and ensure you get the nutrients you need from your food as part of the digestive process.

They can even help regulate your mood!

Look for a quality supplement with multiple human-tested strains of healthy bacteria in high levels -- and by high levels, don't be impressed with "millions" or even "hundreds of millions" of CFUs (or colony-forming units).

Look for something with billions.