After spending approximately 40 weeks inside the womb, the average newborn weighs 7 1/2 pounds. Most babies weigh between 5 1/2 and 10 pounds. The average length of a newborn is 20 inches (50 centimeters), with a range of 18 to 22 inches. The average head circumference (the distance around the head) is 14 inches (35 centimeters).
Lactobacillus and Bifidobacterium are the most common probiotic bacteria. The Lactobacillus genus has 18 different bacteria strains, while the Bifidobacterium genus consists of eight strains.
Antibiotics differ in the types of bacteria they work against. Antibiotics that affect a wide range of bacteria are called broad spectrum antibiotics (e.g. amoxycillin and gentamicin). Antibiotics that affect only a few types of bacteria are called narrow spectrum antibiotics (e.g. penicillin).ntibiotics are used for a range of other infections caused by bacteria, including urinary tract infections, skin infections and infected wounds.