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Fast Fact

The opposite of antibiotics are probiotics - a term coined in 1965 to describe substances that favor the growth of beneficial microorganisms in the body.
Two species of probiotics, Bifidobacterium and Lactobacillus, have been studied the most.
Bacteria that produce the enzyme lactase help reduce lactose intolerance. Probiotics can treat other enzyme deficiencies (e.g. sucrase maltase deficiency) as well.
In a placebo-controlled study, Lactobacillus was given to children along with antibiotics, resulting in fewer cases of diarrhea and milder diarrhea for those who did get it.
Active-culture foods are somewhat effective at preventing and treating bacterial diarrhea, including Clostridium Shigella, Salmonella, and the dreaded E. Coli 0157:H7.
Lactobacillus is most effective at preventing and treating rotavirus and other viral infections.This suggests that probiotics are not just friendly placeholders in the gut, but active immune enhancers.
By reducing inflammation, probiotics appear to be useful in treating a variety of gastrointestinal problems including inflammatory bowel disease (such as Crohn's disease or ulcerative colitis), ulcers, and irritable bowel syndrome. Flatulence and non-specific tummy aches can also be decreased.
Food allergies are caused by the production of antibodies (IgE) against something in the diet. Normally, a substance in our bodies called interleukin (IL-12) prevents this. A recent study showed that consuming Lactobacillus can increase IL-12, decrease IgE antibodies, and thus help prevent and treat food allergies.
Many children with eczema have flare-ups triggered by what they eat or drink. In one fascinating study, a group of children who received Lactobacillus had significant improvement of their eczema within one month!
One of the most startling recent studies of Lactobacillus indicated a "marked, long-term" protective effect on the heart, preventing and decreasing damage from lack of oxygen to the heart muscle. The effect was attributed to the demonstrated changes in inflammation and the immune system.
One double-blind, placebo controlled trial found that some strains of active-culture yogurt, eaten over 8 weeks, help lower LDL cholesterol and normalize blood pressure.Serum triglycerides were also lowered in a controlled animal study.
Because probiotics can decrease the presence of carcinogens in the intestines in several ways, they may prove helpful for preventing cancer. One important study suggests that in the soy-rich Japanese diet that seems to prevent breast cancer, it is the abundance of the probiotic Bifidobacterium in some soy products that is at least partly responsible for the powerful preventive effect.
While active-culture yogurt has proven helpful in many areas, and seems to be helpful in many others, it appears to do nothing to combat vaginal yeast infections. It has been recommended both orally and topically, but when evaluated no benefit is found. Perhaps this is because the normal population of Lactobacillus continues to thrive in the vagina even during a yeast infection.
Lactobacillus can help prevent yeast in the GI tract, diaper area and in the mouth. Probiotics can also help to prevent urinary tract infections.

see Fast Facts about Yogurt and Beneficial Bacteria »

Motion sickness

11.01.2002 Add new comment Send to friend Print this article

Related concepts:

Car sickness, Plane sickness, Seasickness, Space sickness, Height vertigo

Introduction to motion sickness:

Why are people more likely to get car sick in the back seat than in the front? Why are drivers less likely to get car sick than front seat passengers? Why do some people get sick in the car only when they read? On a bumpy flight, why are children more likely than adults to need an airsick bag (and not get to it in time!)?

What is motion sickness?

Our bodies have wonderful mechanisms for sensing and making sense out of motion. There are several important motion-sensing parts of the body. The semicircular canals of the inner ear are like miniature levels that orient the head in space. The eyes also constantly update the brain with information about motion. In addition, the nerves in our joints, especially the ankles, knees, and spine, are motion detectors. Even the light touch sensors of the skin can detect our movement in the air.

Normally, these different sensors provide our brains with a coordinated, immediate sense of how our body is moving, and how the brain should respond.

Motion sickness can result when there is a mismatch between these different systems. If the brain gets conflicting information from the ears and eyes or joints, the histamine receptors in the vomiting centers of the brain may be stimulated to slow down the movement of the GI tract. Even the sight of food can be unpleasant. The brain wants the body to take a break until it can figure things out.

Who gets motion sickness?

Under the right circumstances, anyone can experience motion sickness. Some people are more susceptible to it than others. It tends to be worst on first boat trips or plane rides or space voyages, before the brain has a chance to get used to the new sensations. Sometimes a previous bad experience will trigger a new bout of motion sickness on an even gentler trip. Even anticipation of a ride can trigger symptoms. Either way, motion sickness tends to improve with age and eventually with experience.

Children in the back seat of the car are more susceptible when their height limits their view to seemingly stationary objects in the car. Reading also makes carsickness worse by focusing the attention on something that does not appear to be moving. The inner ears sense motion, but the rest of the body does not.

Some people get vertigo when standing over great heights, because the visual cues of normal body swaying are lost over the great distances.

Some people get queasy, or at least a funny feeling in the stomach, when watching intense motion on a movie screen. The eyes suggest movement; the ears and joints and skin do not.

The most common places for motion sickness are cars, planes, boats, playground equipment, and amusement park rides.

What are the symptoms of motion sickness?

Mild motion sickness usually begins with a funny feeling in the stomach. If the mismatch in motion signals is not resolved to the brain’s satisfaction, the symptoms may progress to include sweating, yawning, crying (in babies), increased saliva, pallor, nausea, and vomiting. Some people also breathe more quickly. Some have a headache. Some even faint.