Like most things, bacteria have their pros and cons. And according to their advocates, probiotics weigh in heavily on the “pro” side.

Recently, probiotics have become a popular addition to many people’s diets. Supplementing your diet with probiotics can be as easy as swallowing a few capsules, or including a container of yogurt with breakfast or as a snack.

More than 45 million Americans experience regular digestive upsets, among them diarrhea, bloating and constipation, according to the StatePoint news service. These symptoms may result from a disturbance in the balance between good and bad bacteria in the digestive tract.

Yet people hear many things about bacteria. Bacterial soap has proliferated, and doctors have prescribed antibiotics to counter many ailments. But these can damage the good bacteria that benefit people. Probiotics can reverse the negative effect these products may have.

“You’re supposed to have about 4 pounds of good bacteria in your intestines,” said Daniel Franke of Oasis Health Foods.

Franke said babies are born without these bacteria and usually acquire them from mother’s milk.

Oasis sells a good number of probiotics in liquid and powder form, or in capsules with or without an enteric coating. Franke recommends the coated capsules because the coating helps the capsule get through the stomach before entering the intestine, which becomes home to the good bacteria.

“They can proliferate once they get in there,” Franke said.

Like a medieval morality play, the intestine is the battleground for war between the good and bad bacteria. Adding to the number of good bacteria present gives that side the odds, warding off digestive disturbances.

“It’s really safe to take. Even if you took a whole bottle, it wouldn’t hurt you,” Franke said. “I’ve heard 30 to 40 percent of your immune system response is based on beneficial bacteria.”

These good bacteria can be disturbed by chlorinated water, antibiotics and prescription drugs in general, he said. When they’re depleted, the body needs to replace them.

Franke said the probiotics also help combat yeast in the digestive system, which can be a factor in gas, bloating and fatigue.

“We’ve had a lot of good feedback from our customers who have used them,” he said.

According to the StatePoint story, factors such as diet, stress level and medication, particularly antibiotics, can disturb the body’s balance of bacteria. It also recommends replacing the beneficial bacteria with a supplement.

Dr. Eamon Quigley of the Alimentary Pharmabiotic Center, University Cork College, Ireland, said people should keep these things in mind when considering probiotics: