The purpose of this small, short pilot study is to determine the feasibility (e.g., recruitment, dose acceptance, retention) of a future longer trial comparing the effects of different types of milk (raw milk, cow's milk, nondairy-milk) on lactose maldigestion.

The goal is to determine if raw milk consumption intake will benefit humans with lactose maldigestion, a common human response to the intake of dairy products during adult years. An increasing number of people are consuming raw unpasteurized milk. Enhanced nutritional qualities, taste, and health benefits have all been advocated as reasons for increased interest in raw milk consumption.

However, science-based data to substantiate these claims are limited or anecdotal.

Raw milk may differ in its ability to improve lactose maldigestion related symptoms from other milk types. Adult lactose maldigestion affects the majority of the world adult population. It appears that consumption of lactose containing foods by those who cannot digest lactose is a relatively common cause of irritable bowel syndrome.

Inclusion Criteria:

• Gender: Both women and men
• Age: > or = 18 years
• Ethnicity and race: All ethnic and racial backgrounds welcome
• Elevation of breath hydrogen after ingestion of 25 g of lactose > 20 ppm over baseline
• Planning to be available for clinic visits for the 6 weeks of study participation
• Ability and willingness to give written informed consent
• No known active psychiatric illness.

Exclusion Criteria:

• Intake of antibiotics or other medications within the past month

• History of diarrheal illness within past month

• Secondary lactase deficiency

• Self reported personal history of:

  *gastrointestinal conditions other than related with lactose maldigestion (IBS, IRB, Short bowel, malabsorption, celiac disease, GI surgery)

• Pregnant or Lactating

• Inability to communicate effectively with study personnel

• Protein allergy related to cow 's milk proteins or soybean proteins