In Autism, Brain, and Environment (2006, ISBN 1-84310-438-5), Lathe proposes that autism is largely a disorder of the limbic brain, balancing evidence that environmental factors may trigger autism with a recognition of genetic vulnerability. In his book, he analyzes biomedical evidence pertaining to the genetics, endocrinology, immunology, toxicology, virology, and neuroscience essential for understanding the causes of autism spectrum disorders (ASDs). Lathe contends that the recent increase in reported ASD cases has resulted from increased exposures to environmental toxics, combined with predisposition to genetic vulnerability. While nothing in his book contradicts research implicating genetic vulnerability as an underlying cause of ASDs, Lathe instead uses evidence showing autism is more prevalent in urban than rural areas to bolster his contention that pollution is a likely culprit as well. Lathe argues that most children on the autism spectrum have additional physiological problems, and that these, rather than being separate from the psychiatric aspects of ASDs, can produce and worsen the condition. “I aim to show how genetics and environmental factors might come together,” he says. Lathe's book also describes a cycle of disease that begins with exposure to certain brain damaging toxins, in particular affecting the limbic system, which in turn can lead to autistic symptoms and collateral physical ailments, such as autistic enterocolitis, leading to further brain damage. With sixty percent of families with a child on the autism spectrum using casein and/or gluten-free diets, Lathe believes that parents are correct in thinking that biomedical intervention can help their children, and that some of these interventions may effectively address environmental causes of ASDs.
Lathe's research has led him to develop a theory that without the Moon, there would be no life on Earth. When life began, Earth orbited much more closely to the Moon than it does now, causing massive tides every few hours, which in turn caused rapid cycling of salinity levels on coastlines and may have driven the evolution of early DNA. Lathe uses polymerase chain reaction (PCR), which amplifies DNA replication in the lab, as an example of the mechanisms that facilitate DNA replication, In the laboratory, PCR synthesis is achieved by cycling DNA between two extreme temperatures in the presence of certain enzymes. At lower temperatures, about 50 °C, single strands of DNA act as templates for building complementary strands. At higher temperatures, about 100 °C, the double strands break apart, doubling the number of molecules. The synthesis of DNA is started again by lowering the temperature, and so forth. Through this process, one DNA molecule can be converted into a trillion identical copies in just 40 cycles. Saline cycles triggered by rapid tidal activity would have amplified molecules such as DNA in a process similar to PCR, says Lathe, "The tidal force is absolutely important, because it provides the energy for association and dissociation" of polymers.