RALEIGH — Fertilizer usually means promoting growth of crops. However, Jack Odle, Ph.D., is studying how feeding prebiotics (indigestible fiber parts of foods) to piglets fertilizes the “good” bacteria in their guts and improves their health while also informing nutrition practices for human newborns.

Odle is the William Neal Reynolds Distinguished Professor of Nutritional Biochemistry at North Carolina State University and member of the UNC School of Medicine’s Center for Gastrointestinal Biology and Disease. He presented at the Animal Health & Nutrition Forum earlier this month at the North Carolina Biotechnology Center.

Jack Odle, Ph.D.

The piglet agri-medical model developed in his laboratory is considered to be the premier model for all mammalian neonates (birth-4 weeks old in humans) including pediatric pre-clinical research.

Joan Torrent, Ph.D., co-owner, co-founder and technical director of Oligo Basics, a developer and manufacturer of functional animal feed additives for agriculture, also addressed how gut health can be managed and animal performance maintained or enhanced in the absence of antibiotics using non-toxic, environmentally friendly functional oils. Functional oils are derived from commonly known oils such as castor oil and cashew nutshell oil and have benefits beyond the energy they provide, such as antioxidant, antimicrobial or anti-inflammatory.

Both experts wowed an audience of life science professionals, academic researchers and students interested in both human and animal health and nutrition at the meeting of the new Animal Health & Nutrition Exchange Group. The AH&N EG is a strategic project of NC Biotech’s Agriculture Sector initiated a year ago to showcase North Carolina’s strengths and growth opportunities in this research and investment space and bring together those within it to exchange ideas and potentially collaborate.

Prebiotics Fertilize Good Gut Bacteria

Odle’s talk focused on prebiotic oligosaccharides, which he said are indigestible carbohydrates that are selectively fermented to allow specific changes in activity of the intestinal microbiota that confers health benefits to the host, in this case piglets 1-28 days old, the model used for human neonates.

“It’s amazing how long it took the infant formula world to wake up to the fact of the great difference in oligosaccharide content … between human breast milk (12 g/L) and cow milk (0.08 g/L), a 150-fold difference. Of course, they immediately became interested in what they could do to supplement these cow milk-based infant formulas to make them more like human breast milk,” he said.

His experiments show how the introduction of prebiotics positively affect growth of good bacteria in the intestines and lowers the pH of the intestinal environment, which reduces the number of pathogenic (bad) bacteria. The bad bacteria cannot grow in a low-pH environment. Overall, the aim is to improve the health and immune response of the gut which is now recognized as an immune organ.

Furthermore, this process leads to production of beneficial xenometabolites by the “second genome,” which Odle said researchers also call the lower gastrointestinal tract. Xenometabolites are compounds produced by the organisms in the lower GI tract that wouldn’t normally be in the body. Some are beneficial and some, like toxins, are not.

Altogether these findings benefit both agriculture and human medicine.

Challenges in Withdrawing Agricultural Antibiotics

Torrent’s talk focused on the role of animal feed additives as replacements for the use of pharmaceutical antibiotics given animals in agriculture to promote growth and prevent disease. He focused specifically on the role of functional oils, on which his company conducts extensive R&D.

He opened by giving two definitions of the term “antibiotic.” For the purposes of science, he said, any antimicrobial compound that acts against bacteria is an antibiotic. However, in terms of regulation, an antibiotic is “whatever the law lists as an antibiotic.”

From there he presented data on the antimicrobial properties of substances consumed for centuries, such as castor oil, which comes from Ricinus communis, a perennial flowering plant, that are natural, nontoxic and environmentally safe. He discussed challenges for the agriculture industry in that man-made antibiotics have been used traditionally to achieve two goals: promote growth and prevent disease in animals.

“The effect on performance of antibiotic growth promoters was 5-15% in the 1950’s, but today is just 1-3% other than in weaned piglets (5%),” he said. The lengthy years-long process of R&D and approval of a new antibiotic has driven many companies out of the animal feed additive market.

Thus, the stage is set to look for alternative naturally occurring substances to add to animal feed that achieves the desired antimicrobial effects in animals, such as those products produced by his company. He then detailed various approaches growers are using to manage different types of agricultural animals so that they can reduce the use of pharmaceutical antibiotics.

Torrent concluded that the industry is indeed adapting to antibiotic withdrawal, however, there is “not going to be a silver bullet,” he said, to replace them. Improvements, he said, are going to come from other approaches, including management of animals differently, such as Europe’s adoption of later weaning times for piglets.