Why On Earth Did We Think Urine Was Sterile?

What was a long-held belief about human urine before recent discoveries?

• It was always acidic.

• It contained many beneficial bacteria.

• It was completely sterile (free of microbes).

• It was primarily composed of blood.

Which part of the human body was historically believed to be entirely free of microbes?

• The stomach

• The skin

• The mouth

• The urinary system

What type of bacteria is responsible for about 75% of urinary tract infections (UTIs)?

• Lactobacillus

• E. coli

• Staphylococcus

• Streptococcus

In an experiment using artificial kidneys, what effect did Lactobacillus have on crystal formation compared to E. coli?

• Lactobacillus caused larger crystals to form.

• Lactobacillus prevented crystal formation entirely.

• Lactobacillus made much smaller crystals, suggesting blocked formation.

• Lactobacillus had no effect on crystal formation.