Instead of using breadcrumbs, you can use a mix of almond flour and Parmesan cheese. This holds it together well. You can also use simply Parmesan cheese by itself; it's a great binder for meatloaf! Alternatively, use another low carb flour substitute, such as golden flaxseed meal, sunflower seed flour, coconut flour, walnut flour, or even unflavored ground pork rinds.