With food chains like Subway, Chipotle, Panera, Chick-fil-A and McDonald’s all now committing to use antibiotic-free chicken , there’s pressure on chicken producers to find alternatives to antibiotics for disease prevention and growth promotion.

That, in turn, is an opportunity for companies like Novozymes. A Danish chemical giant with a long history producing and developing new enzymes, Novozymes is working on probiotic treatments for poultry–one of several promising non-antibiotic technologies being explored by scientists. Probiotics are good bacteria that promote animal (or human) gut health. They can be added to feeds to improve livestocks’ resistance to pathogenic bacteria and potentially–like antibiotics–may promote growth.

Some farmers already use probiotic supplements in their feeds. But Novozymes thinks there’s now an opportunity to expand the market and establish more scientific rigor in the field. Like probiotic human foods, the effectiveness of these treatments is sometimes questioned by scientists (and farmers).

Helle Warrer Poulsen, the company’s vice president for animal health and nutrition, says while probiotics have attracted “true believers” in the industry, there’s still a snake-oil reputation to them. “There is a need and potential to expand the category of microbial solutions by bringing in more science to understand why it works, and under what circumstances,” she says. “This is a pretty rational industry.”

The effectiveness of these treatments is sometimes questioned by scientists.

Novozymes has bought one probiotic producer based in Arkansas. It makes products for poultry hatcheries mainly. And it’s formed a research alliance with Adisseo, a French producer of animal food additives. The groups plan to release their first bacteria-based product in the next six months. DuPont and Calpis are also offering probiotic treatments.

In going “antibiotic free,” retailers and producers normally agree to stop using the drugs for growth promotion–that is, as a normal part of what they feed their animals–but they still may use drugs to treat actual diseases. The probiotics are a form of prevention, hopefully limiting the need for drug delivery both preemptively and after an animal gets sick. The most important animal antibiotics to eliminate are those also used to treat human diseases–that’s how antibiotic-resistant pathogens can come about.

Probiotics aren’t the only antibiotic alternative. Others include antibacterial vaccines, bacteriophages (viruses that kill bacteria), peptides, and plant extracts. These solutions also show promise in reducing the need for antibiotics and, perhaps, eventually in replacing them, although that may take some time yet.