**Contents**



## **About the Editor**

#### **Dennis Savaiano**

Dennis Savaiano is the Virginia Meredith Professor in the Department of Nutrition Science and Dean Emeritus at Purdue University in West Lafayette, Indiana, USA. He earned MS and PhD degrees in Nutrition from the University of California at Davis, and a BA in Biology from Claremont McKenna College. For the past four decades, his research group has studied numerous factors which influence lactose digestion and tolerance, including lactose load, gastric and intestinal transit, the use of lactose digestive aids, the colon fermentation of lactose, and the consumption of fermented dairy foods and lactic acid bacteria. Major findings from these studies include: (1) The identification of a microbial lactase in yogurts that assists lactose digestion in the intestinal tract following the consumption of yogurt. (2) The characterization of the amount of lactose required to cause symptoms in lactose maldigesters as 12 g or more of lactose (one cup of milk). (3) The finding that lactose consumed with a meal is tolerated about three times better than lactose consumed in a fasting state. (4) Identifying the colonic flora as key to determining tolerance to lactose. The colonic flora readily adapt to lactose in the diet of maldigesters. Thus, maldigesters who routinely consume lactose have less symptoms due to the more efficient metabolism of lactose by their colon microflora. (5) The identification of a population of digesters and maldigesters who believe that they are extremely intolerant to lactose, but who tolerate lactose quite well in double-blinded clinical trials. (6) The characterization of the ability of lactic acid bacteria, including acidophilus and bifidus, to improve lactose digestion in vivo in the gastrointestinal system.

## **Preface to "Dairy Products for Human Health"**

The consumption of dairy foods has changed dramatically over the past sixty years in the United States, with much less fluid milk consumed and an increased consumption of cheeses and yogurts. Coffee, sugar-containing beverages, and plant-based milks have replaced much of the fluid milk consumption in the American diet. At the same time, growth in both the international dairy industry and the global consumption of dairy foods has been substantial. Dairy foods are under considerable scrutiny, with concerns relating to the environment and the biological effects of dairy components, including their protein fractions, lipids, lactose, and other nutrients. At the same time, the high nutrient content of dairy foods, including protein, calcium, potassium, and riboflavin, make them a significant contributor to diet quality. Dairy product consumption can influence gut health, weight, cardiometabolic health, diabetes, bone mineral density, and many types of cancers.

This Special Issue of Nutrients aims to collect new scientific evidence addressing health concerns and opportunities related to dairy product consumption. Dairy products play an important role in diet quality and are associated with human health and disease. Our goal is to provide a stronger base of scientific information for the consumer as well as the professionals who advise them on their diet. Both professionals and consumers are undoubtedly confused about the values and risks of dairy foods in the diet due to the limited scientific evidence behind many of the claims made.

> **Dennis Savaiano** *Editor*
