How’s this for a mystery: You have more bacteria living in your small intestine than cells in your body, and your immune system does nothing:

For years, scientists have wondered whether the same mechanism is at work in tissues that come in regular contact with bacteria and other microbial organisms. The small intestine, for example, which absorbs essential nutrients from food and drink and protects the body from invasive microbes, is literally teeming with bacteria, which help break down waste. The presence of so many bacteria is a potential trigger for an immune system response. Why do T cells almost always ignore the small intestine, leaving this vital tissue unharmed?

No, the butler doesn’t do it.

Normally, dendridic cells by displaying antigens teach the immune system what not to attack. But not in the small intestine. Instead, stromal cells in the lymph node do it. Why should you care? Scientist wonder if this method to keep healthy tissue from being attacked by the immune system can’t be used in autoimmune diseases such as Type 1 diabetes and multiple sclerosis.

Tags: intestinal bacteria

It’s just not possible to overstate the importance of intestinal bacteria to your well being. Part of that is simply a fine economy – why should your cells do what 3 pounds of bacteria can acomplish in your gut. The other part is that one dies without the other. Scientists have had a hard time investigating the full toxonomy of your gut flora, mainly because they don’t live well outside you. But scientists have developed a way to find out what’s in there, and the answer is one hell of a lot: more than 60,000 genes (or twice the human genome) and thousands of different strains of bacteria and archaea. So how did they manage to collect this treasure trove?

Rather than struggling to grow the body’s myriad microbes and testing their ability to perform various biochemical reactions — the methods scientists traditionally use to classify bacteria — the team used tiny molecular probes resembling DNA Velcro to retrieve tens of thousands of snippets of bacterial DNA from smidgeons of the intestinal output of two volunteers.

I guess that means they found a way to take the DNA directly from turds without trying to grow any more. Or even worse perhaps, they inserted the probes up into the intestines themselves. Science isn’t always pretty.

My problem isn’t that I eat too much, it’s that my gut bacteria are too efficient. Researchers (from right here in St. Louis) say that the amount of calories you actually extract from food depends on what’s living in your gut. My next question would be how much of what’s in you depends on what’s in your parents? I can just imagine that in the future, we’ll be imbibing different mixtures of gut flora to lose weight or bulk up.

And how about downing a nice mixture of whipworm eggs and gatorade? Yum, yum, but even better than the taste is that it might help people with inflammatory bowel diseases such as Crohn’s. The theory is the worms give your immune system something to do and so it leave the rest of you alone. Needless to say kids, don’t try this at home, wait for an FDA approved treatment.

Tags: intestinal bacteria

A school girl did a wonderful science project – comparing the number of bacteria in the ice they serve you versus the number in their toilet water at fast food restaurants. Her answer is quite unappetizing as she discovered that in most (70%) locations there were more in the ice than there were in the water. Ugh. I do remember that when I was in Pakistan the leader of a detachment of seabees building terrorist defenses at the American Consulate told me how he was fanatic about keeping ice machines clean and disinfected because they could cause illness pretty easily. And don’t even get me started on soft-serve ice cream dispensers.

Beware the people who compare the number of bacteria on some surface to the number of bacteria on a toilet seat — they are misleading you with that comparison because the toilet seat has the fewest number of bacteria of any location in a bathroom – mainly because peoples butts and thighs (and yes, urine) don’t have a lot of bacteria on them, and the (toilet) seats are routinely disinfected. And besides, you can only get skin type infections in the parts of your body that come into contact with the seat, at least if you’re using the toilet properly that is. Generally, toilet seats are down right sterile compared to most other surfaces you regularly come into contact with. If the number of bacteria bug you, stay off the floor of a public restroom.

But the important thing isn’t numbers, but variety of bacteria. For instance, should you be grossed out by that figure of 3 million bacteria on a computer keyboard? Well, when you consider that your very own personal body has 10 times more bacteria than you have cells, or a whopping 100 trillion (give or take a few trillion), that 3 million on the keyboard is insignificant. What matters is if there are any pathogens and your own general health since a lot of stuff that is normally harmless will turn on you if you let your guard down. It doesn’t take many salmonella to ruin your day.

The best defense against bacterial invaders are clean hands and clean food. The 100 trillion that are already there will take care of the stragglers.

Tags: intestinal bacteria

Yes, it’s time to hear about my favorite topic — intestinal bacteria. This time, it’s a downside. The little critters may be responsible for obesity

Friendly bacteria in your gut could determine whether you pack on fat or stay lean, according to new research from Washington University. A team of researchers led by Fredrik Backhed, Dr. Jeffrey I. Gordon and Dr. Clay F. Semenkovich at Washington University discovered that bacteria, which are a normal part of the intestine, help unlock a gate that allows fat to enter cells for storage.

The researchers raised some mice in a germ-free environment. Those animals had no bacteria in their intestines and had little body fat. Mice that grew up in a conventional environment with bacteria in their intestines had 50 percent more body fat than the germ-free mice did, even though the mice ate the same amount of food.

The researchers then transplanted bacteria from the conventionally reared mice into previously germ-free mice. The animals ate no more than before, but dramatically packed on fat, increasing their body fat content 60 percent in two weeks, Gordon said. 

I’m not overweight; I’m over colonized by gut microbes. 

Tags: intestinal bacteria

I’ve been busy (forecast – no clearing in the busyness for a long time), so thankfully Carl has provided a good substantial post below. I’m going to have to go with one of my favorite topics: intestinal bacteria. They have a good side, and a bad side, and the latest is bad — intestinal bacteria cause Crohn’s disease, an unpleasant ailment. Here’s hoping that knowing what strain causes it will lead to a cure.

Tags: intestinal bacteria

Here’s a fun article about flatulence. It reports some of the findings of fart doctor extraordinaire Michael Levitt.

Women and men break wind just as often – although the volume may be lower with each puff.

Loudness and odor are uncorrelated – silent isn’t necessarily deadly (but it sure can be!).

Hydrogen Sulfide not only gives flatus (the technical name for fart) its pungent aroma, but is as deadly as cynanide in the blood stream – no wonder is smells so bad.

This article has not only the the facts about flatulence but also the wonderful phrase “high drama flatulence”.

One of the other benefits to the early stages of the Atkins diet – less flatulence because of the reduction in carbohydrates that fuel the bacteria that make it.

One last thought to leave you with on this subject: you have roughly 10 times more bacteria living in your gut than you have cells in your body, and getting rid of them isn’t an option.

Tags: intestinal bacteria

Science Blog reports that a research group at Washington U. has completed sequencing the genome of one of the most prevalent bacteria in the human gut. The leader of the team, Jeffery Gordon M.D. notes (if you are a clean freak, or squeamish, do not read the following) that the adult human body, is composed of 10 times more microbial cells than human cells. I really hope that’s a misquote.

Tags: intestinal bacteria

In my never ending quest to keep you, my beloved reader, informed on the latest intestinal developments, I link you to another article in Science Blog about intestinal biochemistry. Intrepid researchers right here in River City have discovered just what the heck the molecule MR1 does. Apparently, mucosal-associated invariant t cells (MAIT cells for short and the squeamish) somehow rely on intestinal bacteria and MR1 to keep your gut infection free, a thankless but vital job. The research team has also set its sights higher, to the lungs, to see if MR1 is on the job there, too.

Tags: intestinal bacteria

Well, Medical Science has found something bad about normal intestinal bacteria. It seems that endotoxins released by these bacteria during bypass sugery leads to cognitive decline in patients. Just for the record, I was the astute reader who tipped off Robert Musil to this finding. Yes, I enjoy him so much I remember posts of his from last August. It’s a gift.

Tags: intestinal bacteria

Researchers at Washington University have discovered that intestinal bacteria can cause people (AKA bacterial growth medium) to produce an antibiotic that is specific to invading bacteria. Angiogenins, thought to promote blood vessel growth, apparently are an effective and specific antibiotic (and not only bacteria, but yeast too). Our bodies don’t think all bacteria are bad – not only do we need them for certain vital tasks, we take care not kill those off when we try to kill off the ones that attack us.

You might recall the big hoopla around angiogenins awhile back because researchers discovered they could cure cancer in mice with anti-angiogenic compound – they could starve a tumor by taking away its blood supply. Sadly, it hasn’t seemed to work in humans. Sadly, I couldn’t find a decent link, so you’ll just have to rely on my memory.

Tags: intestinal bacteria